Merge pull request #28509 from vespa-engine/hakonhall/additionalIpAddresses-list

Change primary and pool IPs from Set to List

35 files changed, 186 insertions, 231 deletions

diff --git a/controller-api/src/main/java/com/yahoo/vespa/hosted/controller/api/integration/configserver/Node.java b/controller-api/src/main/java/com/yahoo/vespa/hosted/controller/api/integration/configserver/Node.java
index 0b0664cd3bf..a02cb96272f 100644
--- a/controller-api/src/main/java/com/yahoo/vespa/hosted/controller/api/integration/configserver/Node.java
+++ b/controller-api/src/main/java/com/yahoo/vespa/hosted/controller/api/integration/configserver/Node.java
@@ -15,7 +15,6 @@ import java.util.List;
 import java.util.Map;
 import java.util.Objects;
 import java.util.Optional;
-import java.util.Set;
 import java.util.UUID;
 
 /**
@@ -70,9 +69,9 @@ public class Node {
     private final Optional<ClusterType> exclusiveToClusterType;
     private final Map<String, String> reports;
     private final List<Event> history;
-    private final Set<String> ipAddresses;
-    private final Set<String> additionalIpAddresses;
-    private final Set<String> additionalHostnames;
+    private final List<String> ipAddresses;
+    private final List<String> additionalIpAddresses;
+    private final List<String> additionalHostnames;
     private final Optional<String> switchHostname;
     private final Optional<String> modelName;
     private final Environment environment;
@@ -87,8 +86,8 @@ public class Node {
                  ClusterType clusterType, String group, int index, boolean retired, boolean wantToRetire, boolean wantToDeprovision,
                  boolean wantToRebuild, boolean down, Optional<TenantName> reservedTo, Optional<ApplicationId> exclusiveTo,
                  DockerImage wantedDockerImage, DockerImage currentDockerImage, Optional<ClusterType> exclusiveToClusterType, Map<String, String> reports,
-                 List<Event> history, Set<String> ipAddresses, Set<String> additionalIpAddresses,
-                 Set<String> additionalHostnames, Optional<String> switchHostname,
+                 List<Event> history, List<String> ipAddresses, List<String> additionalIpAddresses,
+                 List<String> additionalHostnames, Optional<String> switchHostname,
                  Optional<String> modelName, Environment environment, CloudAccount cloudAccount) {
         this.id = Objects.requireNonNull(id, "id must be non-null");
         this.hostname = Objects.requireNonNull(hostname, "hostname must be non-null");
@@ -129,9 +128,9 @@ public class Node {
         this.down = down;
         this.reports = Map.copyOf(Objects.requireNonNull(reports, "reports must be non-null"));
         this.history = List.copyOf(Objects.requireNonNull(history, "history must be non-null"));
-        this.ipAddresses = Set.copyOf(Objects.requireNonNull(ipAddresses, "ipAddresses must be non-null"));
-        this.additionalIpAddresses = Set.copyOf(Objects.requireNonNull(additionalIpAddresses, "additionalIpAddresses must be non-null"));
-        this.additionalHostnames = Set.copyOf(Objects.requireNonNull(additionalHostnames, "additionalHostnames must be non-null"));
+        this.ipAddresses = List.copyOf(Objects.requireNonNull(ipAddresses, "ipAddresses must be non-null"));
+        this.additionalIpAddresses = List.copyOf(Objects.requireNonNull(additionalIpAddresses, "additionalIpAddresses must be non-null"));
+        this.additionalHostnames = List.copyOf(Objects.requireNonNull(additionalHostnames, "additionalHostnames must be non-null"));
         this.switchHostname = Objects.requireNonNull(switchHostname, "switchHostname must be non-null");
         this.modelName = Objects.requireNonNull(modelName, "modelName must be non-null");
         this.environment = Objects.requireNonNull(environment, "environment must be non-ull");
@@ -320,17 +319,17 @@ public class Node {
     }
 
     /** IP addresses of this */
-    public Set<String> ipAddresses() {
+    public List<String> ipAddresses() {
         return ipAddresses;
     }
 
     /** Additional IP addresses available on this, usable by child nodes */
-    public Set<String> additionalIpAddresses() {
+    public List<String> additionalIpAddresses() {
         return additionalIpAddresses;
     }
 
     /** Additional hostnames available on this, usable by child nodes */
-    public Set<String> additionalHostnames() {
+    public List<String> additionalHostnames() {
         return additionalHostnames;
     }
 
@@ -502,9 +501,9 @@ public class Node {
         private Optional<ClusterType> exclusiveToClusterType = Optional.empty();
         private Map<String, String> reports = Map.of();
         private List<Event> history = List.of();
-        private Set<String> ipAddresses = Set.of();
-        private Set<String> additionalIpAddresses = Set.of();
-        private Set<String> additionalHostnames = Set.of();
+        private List<String> ipAddresses = List.of();
+        private List<String> additionalIpAddresses = List.of();
+        private List<String> additionalHostnames = List.of();
         private Optional<String> switchHostname = Optional.empty();
         private Optional<String> modelName = Optional.empty();
         private Environment environment = Environment.unknown;
@@ -758,17 +757,17 @@ public class Node {
             return this;
         }
 
-        public Builder ipAddresses(Set<String> ipAdresses) {
+        public Builder ipAddresses(List<String> ipAdresses) {
             this.ipAddresses = ipAdresses;
             return this;
         }
 
-        public Builder additionalIpAddresses(Set<String> additionalIpAddresses) {
+        public Builder additionalIpAddresses(List<String> additionalIpAddresses) {
             this.additionalIpAddresses = additionalIpAddresses;
             return this;
         }
 
-        public Builder additionalHostnames(Set<String> additionalHostnames) {
+        public Builder additionalHostnames(List<String> additionalHostnames) {
             this.additionalHostnames = additionalHostnames;
             return this;
         }
diff --git a/controller-api/src/main/java/com/yahoo/vespa/hosted/controller/api/integration/noderepository/NodeRepositoryNode.java b/controller-api/src/main/java/com/yahoo/vespa/hosted/controller/api/integration/noderepository/NodeRepositoryNode.java
index 34a7c1a6f7c..fd2424694d0 100644
--- a/controller-api/src/main/java/com/yahoo/vespa/hosted/controller/api/integration/noderepository/NodeRepositoryNode.java
+++ b/controller-api/src/main/java/com/yahoo/vespa/hosted/controller/api/integration/noderepository/NodeRepositoryNode.java
@@ -10,7 +10,6 @@ import com.fasterxml.jackson.databind.JsonNode;
 
 import java.util.List;
 import java.util.Map;
-import java.util.Set;
 
 /**
  * The wire format of a node retrieved from the node repository.
@@ -32,9 +31,9 @@ public class NodeRepositoryNode {
     @JsonProperty("hostname")
     private String hostname;
     @JsonProperty("ipAddresses")
-    private Set<String> ipAddresses;
+    private List<String> ipAddresses;
     @JsonProperty("additionalIpAddresses")
-    private Set<String> additionalIpAddresses;
+    private List<String> additionalIpAddresses;
     @JsonProperty("additionalHostnames")
     private List<String> additionalHostnames;
     @JsonProperty("flavor")
@@ -148,19 +147,19 @@ public class NodeRepositoryNode {
         this.hostname = hostname;
     }
 
-    public Set<String> getIpAddresses() {
+    public List<String> getIpAddresses() {
         return ipAddresses;
     }
 
-    public Set<String> getAdditionalIpAddresses() {
+    public List<String> getAdditionalIpAddresses() {
         return additionalIpAddresses;
     }
 
-    public void setIpAddresses(Set<String> ipAddresses) {
+    public void setIpAddresses(List<String> ipAddresses) {
         this.ipAddresses = ipAddresses;
     }
 
-    public void setAdditionalIpAddresses(Set<String> additionalIpAddresses) {
+    public void setAdditionalIpAddresses(List<String> additionalIpAddresses) {
         this.additionalIpAddresses = additionalIpAddresses;
     }
 
diff --git a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/Node.java b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/Node.java
index 8db8e7c2cf8..24159b88a9b 100644
--- a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/Node.java
+++ b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/Node.java
@@ -74,7 +74,7 @@ public final class Node implements Nodelike {
     private final Optional<Allocation> allocation;
 
     /** Creates a node builder in the initial state (reserved) */
-    public static Node.Builder reserve(Set<String> ipAddresses, String hostname, String parentHostname, NodeResources resources, NodeType type) {
+    public static Node.Builder reserve(List<String> ipAddresses, String hostname, String parentHostname, NodeResources resources, NodeType type) {
         return new Node.Builder(UUID.randomUUID().toString(), hostname, new Flavor(resources), State.reserved, type)
                 .ipConfig(IP.Config.ofEmptyPool(ipAddresses))
                 .parentHostname(parentHostname);
@@ -127,11 +127,11 @@ public final class Node implements Nodelike {
 
         if (state == State.ready && type.isHost()) {
             requireNonEmpty(ipConfig.primary(), "A " + type + " must have at least one primary IP address in state " + state);
-            requireNonEmpty(ipConfig.pool().asSet(), "A " + type + " must have a non-empty IP address pool in state " + state);
+            requireNonEmpty(ipConfig.pool().ips(), "A " + type + " must have a non-empty IP address pool in state " + state);
         }
 
         if (parentHostname.isPresent()) {
-            if (!ipConfig.pool().asSet().isEmpty()) throw new IllegalArgumentException("A child node cannot have an IP address pool");
+            if (!ipConfig.pool().ips().isEmpty()) throw new IllegalArgumentException("A child node cannot have an IP address pool");
             if (modelName.isPresent()) throw new IllegalArgumentException("A child node cannot have model name set");
             if (switchHostname.isPresent()) throw new IllegalArgumentException("A child node cannot have switch hostname set");
             if (status.wantToRebuild()) throw new IllegalArgumentException("A child node cannot be rebuilt");
@@ -635,7 +635,7 @@ public final class Node implements Nodelike {
         return value;
     }
 
-    private static Set<String> requireNonEmpty(Set<String> values, String message) {
+    private static List<String> requireNonEmpty(List<String> values, String message) {
         if (values == null || values.isEmpty())
             throw new IllegalArgumentException(message);
         return values;
@@ -828,7 +828,7 @@ public final class Node implements Nodelike {
             return this;
         }
 
-        public Builder ipConfigWithEmptyPool(Set<String> primary) {
+        public Builder ipConfigWithEmptyPool(List<String> primary) {
             this.ipConfig = IP.Config.ofEmptyPool(primary);
             return this;
         }
diff --git a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/NodeList.java b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/NodeList.java
index f355e66b1e4..2d2d8d934d8 100644
--- a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/NodeList.java
+++ b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/NodeList.java
@@ -331,7 +331,7 @@ public class NodeList extends AbstractFilteringList<Node, NodeList> {
     public int eventuallyUnusedIpAddressCount(Node host) {
         // The count in this method relies on the size of the IP address pool if that's non-empty,
         // otherwise fall back to the address/hostname pool.
-        if (host.ipConfig().pool().asSet().isEmpty()) {
+        if (host.ipConfig().pool().ips().isEmpty()) {
             Set<String> allHostnames = cache().keySet();
             return (int) host.ipConfig().pool().hostnames().stream()
                              .filter(hostname -> !allHostnames.contains(hostname.value()))
@@ -341,7 +341,7 @@ public class NodeList extends AbstractFilteringList<Node, NodeList> {
             old != null ? old : stream().flatMap(node -> node.ipConfig().primary().stream())
                                         .collect(Collectors.toUnmodifiableSet())
         );
-        return (int) host.ipConfig().pool().asSet().stream()
+        return (int) host.ipConfig().pool().ips().stream()
                          .filter(address -> !allIps.contains(address))
                          .count();
     }
diff --git a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/CapacityChecker.java b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/CapacityChecker.java
index f3ea326a3c0..d37ef50ca46 100644
--- a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/CapacityChecker.java
+++ b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/CapacityChecker.java
@@ -83,7 +83,7 @@ public class CapacityChecker {
     }
 
     private Optional<HostFailurePath> greedyHeuristicFindFailurePath(Map<Node, Integer> heuristic) {
-        if (hosts.size() == 0) return Optional.empty();
+        if (hosts.isEmpty()) return Optional.empty();
 
         List<Node> parentRemovalPriorityList = heuristic.entrySet().stream()
                                                         .sorted(this::hostMitigationOrder)
@@ -127,12 +127,12 @@ public class CapacityChecker {
         for (var host : hosts) {
             NodeResources hostResources = host.flavor().resources();
             int occupiedIps = 0;
-            Set<String> ipPool = host.ipConfig().pool().asSet();
+            Set<String> ipPool = Set.copyOf(host.ipConfig().pool().ips());
             for (var child : nodeChildren.get(host)) {
                 hostResources = hostResources.subtract(child.resources().justNumbers());
                 occupiedIps += (int)child.ipConfig().primary().stream().filter(ipPool::contains).count();
             }
-            availableResources.put(host, new AllocationResources(hostResources, host.ipConfig().pool().asSet().size() - occupiedIps));
+            availableResources.put(host, new AllocationResources(hostResources, host.ipConfig().pool().ips().size() - occupiedIps));
         }
 
         return availableResources;
diff --git a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/node/IP.java b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/node/IP.java
index ca4b2c99ef0..d9eba6cc8a5 100644
--- a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/node/IP.java
+++ b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/node/IP.java
@@ -14,10 +14,9 @@ import com.yahoo.vespa.hosted.provision.persistence.NameResolver;
 import com.yahoo.vespa.hosted.provision.persistence.NameResolver.RecordType;
 
 import java.net.InetAddress;
-import java.util.Collections;
+import java.util.ArrayList;
 import java.util.Comparator;
 import java.util.HashSet;
-import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Objects;
 import java.util.Optional;
@@ -37,7 +36,7 @@ import static com.yahoo.config.provision.NodeType.proxyhost;
 public record IP() {
 
     /** IP version.  Can be compared with ==, !=, and equals(). */
-    public static class Version {
+    public static class Version implements Comparable<Version> {
         public static final Version v4 = new Version(4);
         public static final Version v6 = new Version(6);
 
@@ -59,6 +58,9 @@ public record IP() {
         public RecordType toForwardRecordType() { return is4() ? RecordType.A : RecordType.AAAA; }
 
         @Override
+        public int compareTo(Version that) { return Integer.compare(this.version, that.version); }
+
+        @Override
         public String toString() { return "IPv" + version; }
 
         @Override
@@ -98,46 +100,33 @@ public record IP() {
         return 0;
     };
 
-    /** IP configuration of a node */
-    public record Config(Set<String> primary, Pool pool) {
-
-        public static final Config EMPTY = Config.ofEmptyPool(Set.of());
+    /**
+     * IP configuration of a node
+     *
+     * @param primary The primary addresses of this. These addresses are used when communicating with the node itself
+     * @param pool    The IP address pool available on a node
+     */
+    public record Config(List<String> primary, Pool pool) {
 
-        public static Config ofEmptyPool(Set<String> primary) {
-            return new Config(primary, Pool.EMPTY);
-        }
+        public static final Config EMPTY = Config.ofEmptyPool();
 
-        public static Config of(Set<String> primary, Set<String> ipPool, List<HostName> hostnames) {
-            return new Config(primary, new Pool(IpAddresses.of(ipPool), hostnames));
-        }
+        public static Config ofEmptyPool(String... primary) { return ofEmptyPool(List.of(primary)); }
+        public static Config ofEmptyPool(List<String> primary) { return of(primary, List.of(), List.of()); }
+        public static Config of(List<String> primary, List<String> ips, List<HostName> hostnames) { return new Config(primary, Pool.of(ips, hostnames)); }
+        public static Config of(List<String> primary, List<String> ips) { return of(primary, ips, List.of()); }
 
-        public static Config of(Set<String> primary, Set<String> pool) {
-            return of(primary, pool, List.of());
-        }
-
-        /** DO NOT USE: Public for NodeSerializer. */
-        public Config(Set<String> primary, Pool pool) {
-            this.primary = Collections.unmodifiableSet(new LinkedHashSet<>(Objects.requireNonNull(primary, "primary must be non-null")));
+        public Config(List<String> primary, Pool pool) {
+            this.primary = List.copyOf(Objects.requireNonNull(primary, "primary must be non-null"));
             this.pool = Objects.requireNonNull(pool, "pool must be non-null");
         }
 
-        /** The primary addresses of this. These addresses are used when communicating with the node itself */
-        public Set<String> primary() {
-            return primary;
-        }
-
-        /** Returns the IP address pool available on a node */
-        public Pool pool() {
-            return pool;
-        }
-
         /** Returns a copy of this with pool set to given value */
         public Config withPool(Pool pool) {
             return new Config(primary, pool);
         }
 
         /** Returns a copy of this with pool set to given value */
-        public Config withPrimary(Set<String> primary) {
+        public Config withPrimary(List<String> primary) {
             return new Config(primary, pool);
         }
 
@@ -157,8 +146,8 @@ public record IP() {
                     var addresses = new HashSet<>(node.ipConfig().primary());
                     var otherAddresses = new HashSet<>(other.ipConfig().primary());
                     if (node.type().isHost()) { // Addresses of a host can never overlap with any other nodes
-                        addresses.addAll(node.ipConfig().pool().asSet());
-                        otherAddresses.addAll(other.ipConfig().pool().asSet());
+                        addresses.addAll(node.ipConfig().pool().ips());
+                        otherAddresses.addAll(other.ipConfig().pool().ips());
                     }
                     otherAddresses.removeIf(otherIp -> !ipSpace.contains(otherIp, other.cloudAccount()));
                     otherAddresses.retainAll(addresses);
@@ -191,15 +180,15 @@ public record IP() {
     }
 
     /** A list of IP addresses and their protocol */
-    record IpAddresses(Set<String> addresses, Stack stack) {
+    record IpAddresses(List<String> addresses, Stack stack) {
 
-        public IpAddresses(Set<String> addresses, Stack stack) {
-            this.addresses = Collections.unmodifiableSet(new LinkedHashSet<>(Objects.requireNonNull(addresses, "addresses must be non-null")));
+        public IpAddresses(List<String> addresses, Stack stack) {
+            this.addresses = List.copyOf(Objects.requireNonNull(addresses, "addresses must be non-null"));
             this.stack = Objects.requireNonNull(stack, "type must be non-null");
         }
 
         /** Create addresses of the given set */
-        private static IpAddresses of(Set<String> addresses) {
+        private static IpAddresses of(List<String> addresses) {
             long ipv6AddrCount = addresses.stream().filter(IP::isV6).count();
             if (ipv6AddrCount == addresses.size()) { // IPv6-only
                 return new IpAddresses(addresses, Stack.ipv6);
@@ -247,12 +236,11 @@ public record IP() {
      */
     public record Pool(IpAddresses ipAddresses, List<HostName> hostnames) {
 
-        public static final Pool EMPTY = new Pool(IpAddresses.of(Set.of()), List.of());
+        public static final Pool EMPTY = Pool.of(List.of(), List.of());
 
-        /** Create a new pool containing given ipAddresses */
-        public static Pool of(Set<String> ipAddresses, List<HostName> hostnames) {
-            IpAddresses ips = IpAddresses.of(ipAddresses);
-            return new Pool(ips, hostnames);
+        /** Create a new pool containing given ips */
+        public static Pool of(List<String> ips, List<HostName> hostnames) {
+            return new Pool(IpAddresses.of(ips), hostnames);
         }
 
         public Pool(IpAddresses ipAddresses, List<HostName> hostnames) {
@@ -260,9 +248,7 @@ public record IP() {
             this.hostnames = List.copyOf(Objects.requireNonNull(hostnames, "hostnames must be non-null"));
         }
 
-        public Set<String> asSet() {
-            return ipAddresses.addresses;
-        }
+        public List<String> ips() { return ipAddresses.addresses; }
 
         /**
          * Find a free allocation in this pool. Note that the allocation is not final until it is assigned to a node
@@ -278,7 +264,7 @@ public record IP() {
                                                  .findFirst();
             }
 
-            Set<String> unusedIps = findUnusedIpAddresses(nodes);
+            List<String> unusedIps = findUnusedIpAddresses(nodes);
 
             if (context.allocateFromUnusedHostname())
                 return findUnusedHostnames(nodes).findFirst().map(hostname -> Allocation.fromHostname(context, hostname, ipAddresses.stack, unusedIps));
@@ -308,11 +294,11 @@ public record IP() {
          *
          * @param nodes a list of all nodes in the repository
          */
-        public Set<String> findUnusedIpAddresses(NodeList nodes) {
-            Set<String> unusedAddresses = new LinkedHashSet<>(asSet());
-            nodes.matching(node -> node.ipConfig().primary().stream().anyMatch(ip -> asSet().contains(ip)))
+        public List<String> findUnusedIpAddresses(NodeList nodes) {
+            List<String> unusedAddresses = new ArrayList<>(ips());
+            nodes.matching(node -> node.ipConfig().primary().stream().anyMatch(ip -> ips().contains(ip)))
                  .forEach(node -> unusedAddresses.removeAll(node.ipConfig().primary()));
-            return Collections.unmodifiableSet(unusedAddresses);
+            return unusedAddresses;
         }
 
         private Stream<HostName> findUnusedHostnames(NodeList nodes) {
@@ -320,7 +306,7 @@ public record IP() {
             return hostnames.stream().filter(hostname -> !usedHostnames.contains(hostname.value()));
         }
 
-        public Pool withIpAddresses(Set<String> ipAddresses) {
+        public Pool withIpAddresses(List<String> ipAddresses) {
             return Pool.of(ipAddresses, hostnames);
         }
 
@@ -423,13 +409,13 @@ public record IP() {
             return new Allocation(hostname4, Optional.of(addresses.get(0)), Optional.empty());
         }
 
-        private static Allocation fromHostname(Context context, HostName hostname, IpAddresses.Stack stack, Set<String> unusedIps) {
+        private static Allocation fromHostname(Context context, HostName hostname, IpAddresses.Stack stack, List<String> unusedIps) {
             Optional<String> ipv4Address = resolveAndVerify(context, hostname, stack, IP.Version.v4, unusedIps);
             Optional<String> ipv6Address = resolveAndVerify(context, hostname, stack, IP.Version.v6, unusedIps);
             return new Allocation(hostname.value(), ipv4Address, ipv6Address);
         }
 
-        private static Optional<String> resolveAndVerify(Context context, HostName hostname, IpAddresses.Stack stack, Version version, Set<String> unusedIps) {
+        private static Optional<String> resolveAndVerify(Context context, HostName hostname, IpAddresses.Stack stack, Version version, List<String> unusedIps) {
             if (context.hasIpNotInDns(version)) {
                 List<String> candidates = unusedIps.stream()
                                                    .filter(a -> IP.Version.fromIpAddress(a).equals(version))
@@ -463,9 +449,8 @@ public record IP() {
         }
 
         /** All IP addresses in this */
-        public Set<String> addresses() {
-            return Stream.concat(ipv4Address.stream(), ipv6Address.stream())
-                         .collect(Collectors.toUnmodifiableSet());
+        public List<String> addresses() {
+            return Stream.concat(ipv4Address.stream(), ipv6Address.stream()).toList();
         }
 
     }
diff --git a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/persistence/NodeSerializer.java b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/persistence/NodeSerializer.java
index 358c94895d1..870e678a250 100644
--- a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/persistence/NodeSerializer.java
+++ b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/persistence/NodeSerializer.java
@@ -1,7 +1,6 @@
 // Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.hosted.provision.persistence;
 
-import com.google.common.collect.ImmutableSet;
 import com.yahoo.component.Version;
 import com.yahoo.config.provision.ApplicationId;
 import com.yahoo.config.provision.ApplicationName;
@@ -41,7 +40,6 @@ import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
 import java.util.Optional;
-import java.util.Set;
 
 /**
  * Serializes a node to/from JSON.
@@ -153,8 +151,8 @@ public class NodeSerializer {
     private void toSlime(Node node, Cursor object) {
         object.setString(hostnameKey, node.hostname());
         object.setString(stateKey, toString(node.state()));
-        toSlime(node.ipConfig().primary(), object.setArray(ipAddressesKey));
-        toSlime(node.ipConfig().pool().asSet(), object.setArray(ipAddressPoolKey));
+        toSlime(node.ipConfig().primary(), object.setArray(ipAddressesKey), true);
+        toSlime(node.ipConfig().pool().ips(), object.setArray(ipAddressPoolKey), true);
         toSlime(node.ipConfig().pool().hostnames(), object);
         object.setString(idKey, node.id());
         node.extraId().ifPresent(id -> object.setString(extraIdKey, id));
@@ -233,10 +231,10 @@ public class NodeSerializer {
         object.setString(agentKey, toString(event.agent()));
     }
 
-    private void toSlime(Set<String> ipAddresses, Cursor array) {
+    private void toSlime(List<String> addresses, Cursor array, boolean dummyDueToErasure) {
         // Validating IP address string literals is expensive, so we do it at serialization time instead of Node
         // construction time
-        ipAddresses.stream().map(IP::parse).sorted(IP.NATURAL_ORDER).map(IP::asString).forEach(array::addString);
+        addresses.stream().map(IP::parse).sorted(IP.NATURAL_ORDER).map(IP::asString).forEach(array::addString);
     }
 
     private void toSlime(List<HostName> hostnames, Cursor object) {
@@ -380,10 +378,10 @@ public class NodeSerializer {
         return SlimeUtils.optionalString(object).map(DockerImage::fromString);
     }
 
-    private Set<String> ipAddressesFromSlime(Inspector object, String key) {
-        ImmutableSet.Builder<String> ipAddresses = ImmutableSet.builder();
+    private List<String> ipAddressesFromSlime(Inspector object, String key) {
+        var ipAddresses = new ArrayList<String>();
         object.field(key).traverse((ArrayTraverser) (i, item) -> ipAddresses.add(item.asString()));
-        return ipAddresses.build();
+        return ipAddresses;
     }
 
     private List<HostName> hostnamesFromSlime(Inspector object) {
diff --git a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/provisioning/ProvisionedHost.java b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/provisioning/ProvisionedHost.java
index c9fd1d08759..460b1bd23a0 100644
--- a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/provisioning/ProvisionedHost.java
+++ b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/provisioning/ProvisionedHost.java
@@ -18,7 +18,6 @@ import java.time.Duration;
 import java.util.List;
 import java.util.Objects;
 import java.util.Optional;
-import java.util.Set;
 
 /**
  * Describes a single newly provisioned host by {@link HostProvisioner}.
@@ -65,7 +64,7 @@ public class ProvisionedHost {
 
     /** Generate {@link Node} instance representing the provisioned physical host */
     public Node generateHost(Duration hostTTL) {
-        Node.Builder builder = Node.create(id, IP.Config.of(Set.of(), Set.of(), nodeHostnames), hostHostname, hostFlavor, hostType)
+        Node.Builder builder = Node.create(id, IP.Config.of(List.of(), List.of(), nodeHostnames), hostHostname, hostFlavor, hostType)
                                    .status(Status.initial().withOsVersion(OsVersion.EMPTY.withCurrent(Optional.of(osVersion))))
                                    .cloudAccount(cloudAccount);
         exclusiveToApplicationId.ifPresent(builder::exclusiveToApplicationId);
@@ -76,7 +75,7 @@ public class ProvisionedHost {
 
     /** Generate {@link Node} instance representing the node running on this physical host */
     public Node generateNode() {
-        return Node.reserve(Set.of(), nodeHostname(), hostHostname, nodeResources, hostType.childNodeType())
+        return Node.reserve(List.of(), nodeHostname(), hostHostname, nodeResources, hostType.childNodeType())
                    .cloudAccount(cloudAccount)
                    .build();
     }
diff --git a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/restapi/NodePatcher.java b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/restapi/NodePatcher.java
index 5915f02ec4f..9f1ab3dc3d5 100644
--- a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/restapi/NodePatcher.java
+++ b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/restapi/NodePatcher.java
@@ -41,7 +41,6 @@ import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 import java.util.Set;
-import java.util.TreeSet;
 import java.util.stream.Stream;
 
 import static com.yahoo.config.provision.NodeResources.DiskSpeed.fast;
@@ -282,8 +281,8 @@ public class NodePatcher {
 
     private Node applyIpconfigField(Node node, String name, Inspector value, LockedNodeList nodes) {
         return switch (name) {
-            case "ipAddresses" -> IP.Config.verify(node.with(node.ipConfig().withPrimary(asStringSet(value))), nodes, nodeRepository.zone());
-            case "additionalIpAddresses" -> IP.Config.verify(node.with(node.ipConfig().withPool(node.ipConfig().pool().withIpAddresses(asStringSet(value)))), nodes, nodeRepository.zone());
+            case "ipAddresses" -> IP.Config.verify(node.with(node.ipConfig().withPrimary(asStringList(value))), nodes, nodeRepository.zone());
+            case "additionalIpAddresses" -> IP.Config.verify(node.with(node.ipConfig().withPool(node.ipConfig().pool().withIpAddresses(asStringList(value)))), nodes, nodeRepository.zone());
             case "additionalHostnames" -> IP.Config.verify(node.with(node.ipConfig().withPool(node.ipConfig().pool().withHostnames(asHostnames(value)))), nodes, nodeRepository.zone());
             default -> throw new IllegalArgumentException("Could not apply field '" + name + "' on a node: No such modifiable field");
         };
@@ -336,11 +335,11 @@ public class NodePatcher {
         return node.with(trustStoreItems);
     }
 
-    private Set<String> asStringSet(Inspector field) {
+    private List<String> asStringList(Inspector field) {
         if ( ! field.type().equals(Type.ARRAY))
             throw new IllegalArgumentException("Expected an ARRAY value, got a " + field.type());
 
-        TreeSet<String> strings = new TreeSet<>();
+        var strings = new ArrayList<String>();
         for (int i = 0; i < field.entries(); i++) {
             Inspector entry = field.entry(i);
             if ( ! entry.type().equals(Type.STRING))
diff --git a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/restapi/NodesResponse.java b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/restapi/NodesResponse.java
index e3960cc5db5..2b908efde94 100644
--- a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/restapi/NodesResponse.java
+++ b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/restapi/NodesResponse.java
@@ -182,7 +182,7 @@ class NodesResponse extends SlimeJsonResponse {
         toSlime(node.history().events(), object.setArray("history"));
         toSlime(node.history().log(), object.setArray("log"));
         ipAddressesToSlime(node.ipConfig().primary(), object.setArray("ipAddresses"));
-        ipAddressesToSlime(node.ipConfig().pool().asSet(), object.setArray("additionalIpAddresses"));
+        ipAddressesToSlime(node.ipConfig().pool().ips(), object.setArray("additionalIpAddresses"));
         hostnamesToSlime(node.ipConfig().pool().hostnames(), object);
         node.reports().toSlime(object, "reports");
         node.modelName().ifPresent(modelName -> object.setString("modelName", modelName));
diff --git a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/restapi/NodesV2ApiHandler.java b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/restapi/NodesV2ApiHandler.java
index 28f99b02e60..79dc7fe72a8 100644
--- a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/restapi/NodesV2ApiHandler.java
+++ b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/restapi/NodesV2ApiHandler.java
@@ -55,7 +55,6 @@ import java.net.URI;
 import java.net.URISyntaxException;
 import java.util.ArrayList;
 import java.util.Collection;
-import java.util.HashSet;
 import java.util.List;
 import java.util.Optional;
 import java.util.Set;
@@ -282,9 +281,9 @@ public class NodesV2ApiHandler extends ThreadedHttpRequestHandler {
     }
 
     private Node createNode(Inspector inspector) {
-        Set<String> ipAddresses = new HashSet<>();
+        var ipAddresses = new ArrayList<String>();
         inspector.field("ipAddresses").traverse((ArrayTraverser) (i, item) -> ipAddresses.add(item.asString()));
-        Set<String> ipAddressPool = new HashSet<>();
+        var ipAddressPool = new ArrayList<String>();
         inspector.field("additionalIpAddresses").traverse((ArrayTraverser) (i, item) -> ipAddressPool.add(item.asString()));
 
         List<HostName> hostnames = new ArrayList<>();
diff --git a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/testutils/MockHostProvisioner.java b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/testutils/MockHostProvisioner.java
index 03923853594..5cdb08d6fc6 100644
--- a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/testutils/MockHostProvisioner.java
+++ b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/testutils/MockHostProvisioner.java
@@ -109,7 +109,7 @@ public class MockHostProvisioner implements HostProvisioner {
         Map<String, IP.Config> result = new HashMap<>();
         result.put(host.hostname(), createIpConfig(host));
         host.ipConfig().pool().hostnames().forEach(hostname ->
-                result.put(hostname.value(), IP.Config.ofEmptyPool(nameResolver.resolveAll(hostname.value()))));
+                result.put(hostname.value(), IP.Config.ofEmptyPool(List.copyOf(nameResolver.resolveAll(hostname.value())))));
         return new HostIpConfig(result, Optional.empty());
     }
 
@@ -238,8 +238,8 @@ public class MockHostProvisioner implements HostProvisioner {
     public IP.Config createIpConfig(Node node) {
         if (!node.type().isHost()) throw new IllegalArgumentException("Node " + node + " is not a host");
         int hostIndex = Integer.parseInt(node.hostname().replaceAll("^[a-z]+|-\\d+$", ""));
-        Set<String> addresses = Set.of("::" + hostIndex + ":0");
-        Set<String> ipAddressPool = new HashSet<>();
+        var addresses = List.of("::" + hostIndex + ":0");
+        var ipAddressPool = new ArrayList<String>();
         if (!behaviour(Behaviour.failDnsUpdate)) {
             nameResolver.addRecord(node.hostname(), addresses.iterator().next());
             int i = 1;
diff --git a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/testutils/MockNodeRepository.java b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/testutils/MockNodeRepository.java
index 086639d7276..72225763381 100644
--- a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/testutils/MockNodeRepository.java
+++ b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/testutils/MockNodeRepository.java
@@ -52,7 +52,6 @@ import java.time.Clock;
 import java.time.Instant;
 import java.time.ZoneId;
 import java.util.ArrayList;
-import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Optional;
 
@@ -274,8 +273,8 @@ public class MockNodeRepository extends NodeRepository {
     }
 
     private IP.Config ipConfig(int nodeIndex, int primarySize, int poolSize) {
-        var primary = new LinkedHashSet<String>();
-        var ipPool = new LinkedHashSet<String>();
+        var primary = new ArrayList<String>();
+        var ipPool = new ArrayList<String>();
         for (int i = 1; i <= primarySize + poolSize; i++) {
             var set = primary;
             if (i > primarySize) {
diff --git a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/NodeListMicroBenchmarkTest.java b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/NodeListMicroBenchmarkTest.java
index 85338bdb2b4..b275cb8a4c6 100644
--- a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/NodeListMicroBenchmarkTest.java
+++ b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/NodeListMicroBenchmarkTest.java
@@ -16,12 +16,9 @@ import java.time.Duration;
 import java.time.Instant;
 import java.util.ArrayList;
 import java.util.Collection;
-import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Optional;
 import java.util.Random;
-import java.util.Set;
-import java.util.stream.Collectors;
 
 /**
  * @author hmusum
@@ -64,7 +61,7 @@ public class NodeListMicroBenchmarkTest {
     private List<Node> createHosts() {
         List<Node> hosts = new ArrayList<>();
         for (int i = 0; i < hostCount; i++) {
-            hosts.add(Node.create("host" + i, IP.Config.of(Set.of("::1"), createIps(), List.of()),
+            hosts.add(Node.create("host" + i, IP.Config.of(List.of("::1"), createIps(), List.of()),
                                "host" + i, getFlavor("host"), NodeType.host).build());
         }
         return hosts;
@@ -74,7 +71,7 @@ public class NodeListMicroBenchmarkTest {
         List<Node> nodes = new ArrayList<>();
         for (int i = 0; i < 10; i++) {
             nodeCounter++;
-            Node node = Node.reserve(Set.of("::2"), "node" + nodeCounter, parentHostname, resources0, NodeType.tenant).build();
+            Node node = Node.reserve(List.of("::2"), "node" + nodeCounter, parentHostname, resources0, NodeType.tenant).build();
             nodes.add(node);
         }
         return nodes;
@@ -92,11 +89,11 @@ public class NodeListMicroBenchmarkTest {
         return nodeFlavors.getFlavor(name).orElseThrow(() -> new RuntimeException("Unknown flavor"));
     }
 
-    private Set<String> createIps() {
+    private List<String> createIps() {
         // Allow 4 containers
         int start = 2;
         int count = 4;
-        Set<String> ipAddressPool = new LinkedHashSet<>();
+        var ipAddressPool = new ArrayList<String>();
         for (int i = start; i < (start + count); i++) {
             ipAddressPool.add("::" + i);
         }
diff --git a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/NodeRepositoryTest.java b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/NodeRepositoryTest.java
index 5148d2a635c..852502c2f4f 100644
--- a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/NodeRepositoryTest.java
+++ b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/NodeRepositoryTest.java
@@ -64,9 +64,9 @@ public class NodeRepositoryTest {
                             Environment.prod,
                             RegionName.from("aws-us-east-1a"));
         NodeRepositoryTester tester = new NodeRepositoryTester(zone);
-        IP.Config ipConfig = IP.Config.of(Set.of("1.2.3.4", "10.2.3.4"), Set.of("1.2.3.4", "10.2.3.4"));
-        IP.Config publicIpConfig = IP.Config.of(Set.of("1.2.3.4"), Set.of("1.2.3.4"));
-        IP.Config privateIpConfig = IP.Config.of(Set.of("10.2.3.4"), Set.of("10.2.3.4"));
+        IP.Config ipConfig = IP.Config.of(List.of("1.2.3.4", "10.2.3.4"), List.of("1.2.3.4", "10.2.3.4"));
+        IP.Config publicIpConfig = IP.Config.of(List.of("1.2.3.4"), List.of("1.2.3.4"));
+        IP.Config privateIpConfig = IP.Config.of(List.of("10.2.3.4"), List.of("10.2.3.4"));
 
         Node host1 = Node.create("id1", ipConfig, "host1", tester.nodeFlavors().getFlavorOrThrow("default"), NodeType.host)
                                .build();
diff --git a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/NodeRepositoryTester.java b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/NodeRepositoryTester.java
index bf714cd9df1..a6cdcd0b998 100644
--- a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/NodeRepositoryTester.java
+++ b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/NodeRepositoryTester.java
@@ -20,7 +20,6 @@ import com.yahoo.vespa.hosted.provision.testutils.OrchestratorMock;
 
 import java.util.List;
 import java.util.Optional;
-import java.util.Set;
 
 /**
  * @author bratseth
@@ -78,8 +77,8 @@ public class NodeRepositoryTester {
     }
 
     private Node addNode(String id, String hostname, String parentHostname, Flavor flavor, NodeType type) {
-        Set<String> ips = nodeRepository.nameResolver().resolveAll(hostname);
-        IP.Config ipConfig = IP.Config.of(ips, type.isHost() ? ips : Set.of());
+        List<String> ips = List.copyOf(nodeRepository.nameResolver().resolveAll(hostname));
+        IP.Config ipConfig = IP.Config.of(ips, type.isHost() ? ips : List.of());
         Node node = Node.create(id, ipConfig, hostname, flavor, type).parentHostname(parentHostname).build();
         return nodeRepository.nodes().addNodes(List.of(node), Agent.system).get(0);
     }
diff --git a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/CapacityCheckerTester.java b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/CapacityCheckerTester.java
index eedf4946e3a..5544251f021 100644
--- a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/CapacityCheckerTester.java
+++ b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/CapacityCheckerTester.java
@@ -43,8 +43,6 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
-import java.util.Set;
-import java.util.stream.Collectors;
 import java.util.stream.IntStream;
 
 import static org.junit.Assert.assertTrue;
@@ -108,8 +106,8 @@ public class CapacityCheckerTester {
                         child.minMainMemoryAvailableGb = cnr.memoryGb();
                         child.minDiskAvailableGb = cnr.diskGb();
                         child.fastDisk = true;
-                        child.ipAddresses = Set.of();
-                        child.additionalIpAddresses = Set.of();
+                        child.ipAddresses = List.of();
+                        child.additionalIpAddresses = List.of();
                         child.owner = new NodeModel.OwnerModel();
                         child.owner.tenant = tenant + j / childCombinations;
                         child.owner.application = application;
@@ -140,7 +138,7 @@ public class CapacityCheckerTester {
                 String childHostName = parentName + "-v6-" + k + parentRoot;
                 childModel.id = childHostName;
                 childModel.hostname = childHostName;
-                childModel.ipAddresses = Set.of(String.format("%04X::%04X", i, k));
+                childModel.ipAddresses = List.of(String.format("%04X::%04X", i, k));
                 childModel.membership.index = j / distinctChildren.size();
                 childModel.parentHostname = Optional.of(hostname);
 
@@ -151,12 +149,12 @@ public class CapacityCheckerTester {
             }
 
             final int hostindex = i;
-            Set<String> availableIps = IntStream.range(0, childrenPerHost + excessIps)
+            List<String> availableIps = IntStream.range(0, childrenPerHost + excessIps)
                     .mapToObj(n -> String.format("%04X::%04X", hostindex, n))
-                    .collect(Collectors.toSet());
+                    .toList();
 
             NodeResources nr = containingNodeResources(childResources, excessCapacity);
-            Node node = Node.create(hostname, IP.Config.of(Set.of("::"), availableIps), hostname,
+            Node node = Node.create(hostname, IP.Config.of(List.of("::"), availableIps), hostname,
                                     new Flavor(nr), NodeType.host).build();
             hosts.computeIfAbsent(tenantHostApp, (ignored) -> new ArrayList<>())
                  .add(node);
@@ -172,10 +170,10 @@ public class CapacityCheckerTester {
             String hostname = parentName + parentRoot;
 
             final int hostId = i;
-            Set<String> availableIps = IntStream.range(2000, 2000 + ips)
+            List<String> availableIps = IntStream.range(2000, 2000 + ips)
                     .mapToObj(n -> String.format("%04X::%04X", hostId, n))
-                    .collect(Collectors.toSet());
-            Node node = Node.create(hostname, IP.Config.of(Set.of("::" + (1000 + hostId)), availableIps), hostname,
+                    .toList();
+            Node node = Node.create(hostname, IP.Config.of(List.of("::" + (1000 + hostId)), availableIps), hostname,
                                     new Flavor(capacity), NodeType.host).build();
             hosts.add(node);
         }
@@ -256,8 +254,8 @@ public class CapacityCheckerTester {
         @JsonProperty double minCpuCores;
         @JsonProperty double bandwidth;
         @JsonProperty boolean fastDisk;
-        @JsonProperty Set<String> ipAddresses;
-        @JsonProperty Set<String> additionalIpAddresses;
+        @JsonProperty List<String> ipAddresses;
+        @JsonProperty List<String> additionalIpAddresses;
 
         @JsonProperty OwnerModel owner;
         @JsonProperty MembershipModel membership;
diff --git a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/HostCapacityMaintainerTest.java b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/HostCapacityMaintainerTest.java
index d51a3e72622..549237441c8 100644
--- a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/HostCapacityMaintainerTest.java
+++ b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/HostCapacityMaintainerTest.java
@@ -61,7 +61,6 @@ import java.util.Collections;
 import java.util.Comparator;
 import java.util.List;
 import java.util.Optional;
-import java.util.Set;
 import java.util.function.Supplier;
 import java.util.stream.Stream;
 
@@ -847,7 +846,7 @@ public class HostCapacityMaintainerTest {
                             false));
             List<com.yahoo.config.provision.HostName> hostnames = Stream.of(additionalHostnames).map(com.yahoo.config.provision.HostName::of).toList();
             Node.Builder builder = Node.create("fake-id-" + hostname, hostname, flavor, state, nodeType)
-                                       .ipConfig(IP.Config.of(state == Node.State.active ? Set.of("::1") : Set.of(), Set.of(), hostnames))
+                                       .ipConfig(IP.Config.of(state == Node.State.active ? List.of("::1") : List.of(), List.of(), hostnames))
                                        .hostTTL(hostTTL);
             parentHostname.ifPresent(builder::parentHostname);
             allocation.ifPresent(builder::allocation);
diff --git a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/HostResumeProvisionerTest.java b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/HostResumeProvisionerTest.java
index f7c9d46801c..165e120e781 100644
--- a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/HostResumeProvisionerTest.java
+++ b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/HostResumeProvisionerTest.java
@@ -59,10 +59,10 @@ public class HostResumeProvisionerTest {
         Node host = tester.nodeRepository().nodes().node("host100").orElseThrow();
         Node node = tester.nodeRepository().nodes().node("host100-1").orElseThrow();
         assertTrue("No IP addresses assigned",
-                Stream.of(host, node).map(n -> n.ipConfig().primary()).allMatch(Set::isEmpty));
+                Stream.of(host, node).map(n -> n.ipConfig().primary()).allMatch(List::isEmpty));
 
-        Node hostNew = host.with(host.ipConfig().withPrimary(Set.of("::100:0")).withPool(host.ipConfig().pool().withIpAddresses(Set.of("::100:1", "::100:2"))));
-        Node nodeNew = node.with(IP.Config.ofEmptyPool(Set.of("::100:1")));
+        Node hostNew = host.with(host.ipConfig().withPrimary(List.of("::100:0")).withPool(host.ipConfig().pool().withIpAddresses(List.of("::100:1", "::100:2"))));
+        Node nodeNew = node.with(IP.Config.ofEmptyPool("::100:1"));
 
         hostResumeProvisioner.maintain();
         assertEquals(hostNew.ipConfig(), tester.nodeRepository().nodes().node("host100").get().ipConfig());
@@ -79,12 +79,12 @@ public class HostResumeProvisionerTest {
         hostResumeProvisioner.maintain();
 
         assertTrue("No IP addresses written as DNS updates are failing",
-                provisioning.get().stream().allMatch(host -> host.ipConfig().pool().asSet().isEmpty()));
+                provisioning.get().stream().allMatch(host -> host.ipConfig().pool().ips().isEmpty()));
 
         hostProvisioner.without(MockHostProvisioner.Behaviour.failDnsUpdate);
         hostResumeProvisioner.maintain();
         assertTrue("IP addresses written as DNS updates are succeeding",
-                provisioning.get().stream().noneMatch(host -> host.ipConfig().pool().asSet().isEmpty()));
+                provisioning.get().stream().noneMatch(host -> host.ipConfig().pool().ips().isEmpty()));
     }
 
     @Test
@@ -95,7 +95,7 @@ public class HostResumeProvisionerTest {
         Node host = tester.nodeRepository().nodes().node("host100").orElseThrow();
         Node node = tester.nodeRepository().nodes().node("host100-1").orElseThrow();
         assertTrue("No IP addresses assigned",
-                Stream.of(host, node).map(n -> n.ipConfig().primary()).allMatch(Set::isEmpty));
+                Stream.of(host, node).map(n -> n.ipConfig().primary()).allMatch(List::isEmpty));
 
         hostResumeProvisioner.maintain();
         assertEquals(Set.of("host100", "host100-1"), tester.nodeRepository().nodes().list(Node.State.failed).hostnames());
diff --git a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/MetricsReporterTest.java b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/MetricsReporterTest.java
index 3091f82143d..1e2a6805ad1 100644
--- a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/MetricsReporterTest.java
+++ b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/MetricsReporterTest.java
@@ -190,22 +190,22 @@ public class MetricsReporterTest {
         NodeRepository nodeRepository = tester.nodeRepository();
 
         // Allow 4 containers
-        Set<String> ipAddressPool = Set.of("::2", "::3", "::4", "::5");
+        var ipAddressPool = List.of("::2", "::3", "::4", "::5");
 
-        Node dockerHost = Node.create("node-id-1", IP.Config.of(Set.of("::1"), ipAddressPool), "dockerHost",
+        Node dockerHost = Node.create("node-id-1", IP.Config.of(List.of("::1"), ipAddressPool), "dockerHost",
                                       nodeFlavors.getFlavorOrThrow("host"), NodeType.host).build();
         nodeRepository.nodes().addNodes(List.of(dockerHost), Agent.system);
         nodeRepository.nodes().deallocateRecursively("dockerHost", Agent.system, getClass().getSimpleName());
         tester.move(Node.State.ready, "dockerHost");
 
-        Node container1 = Node.reserve(Set.of("::2"), "container1",
+        Node container1 = Node.reserve(List.of("::2"), "container1",
                                        "dockerHost", new NodeResources(1, 3, 2, 1), NodeType.tenant).build();
         container1 = container1.with(allocation(Optional.of("app1"), container1).get());
         try (Mutex lock = nodeRepository.nodes().lockUnallocated()) {
             nodeRepository.nodes().addReservedNodes(new LockedNodeList(List.of(container1), lock));
         }
 
-        Node container2 = Node.reserve(Set.of("::3"), "container2",
+        Node container2 = Node.reserve(List.of("::3"), "container2",
                                        "dockerHost", new NodeResources(2, 4, 4, 1), NodeType.tenant).build();
         container2 = container2.with(allocation(Optional.of("app2"), container2).get());
         try (Mutex lock = nodeRepository.nodes().lockUnallocated()) {
diff --git a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/NodeFailTester.java b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/NodeFailTester.java
index 00ae9ac5a9d..384c511dfe5 100644
--- a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/NodeFailTester.java
+++ b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/NodeFailTester.java
@@ -242,8 +242,8 @@ public class NodeFailTester {
         int lastOctetOfPoolAddress = 0;
         for (int i = startIndex; i < startIndex + count; i++) {
             String hostname = "host" + i;
-            Set<String> ipPool = nodeType.isHost() ? Set.of("127.0." + i + "." + (++lastOctetOfPoolAddress)) : Set.of();
-            IP.Config ipConfig = IP.Config.of(nodeRepository.nameResolver().resolveAll(hostname),
+            List<String> ipPool = nodeType.isHost() ? List.of("127.0." + i + "." + (++lastOctetOfPoolAddress)) : List.of();
+            IP.Config ipConfig = IP.Config.of(List.copyOf(nodeRepository.nameResolver().resolveAll(hostname)),
                                               ipPool);
             Node.Builder builder = Node.create("node" + i, ipConfig, hostname, flavor, nodeType);
             parentHostname.ifPresent(builder::parentHostname);
diff --git a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/RetiredExpirerTest.java b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/RetiredExpirerTest.java
index d0ac59b1e15..5e39602145a 100644
--- a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/RetiredExpirerTest.java
+++ b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/RetiredExpirerTest.java
@@ -237,7 +237,7 @@ public class RetiredExpirerTest {
         MockNameResolver nameResolver = (MockNameResolver) tester.nodeRepository().nameResolver();
         String ipv4 = "127.0.1.4";
         nameResolver.addRecord(retiredNode.hostname(), ipv4);
-        Node node = Node.create(retiredNode.hostname(), IP.Config.of(Set.of(ipv4), Set.of()), retiredNode.hostname(),
+        Node node = Node.create(retiredNode.hostname(), IP.Config.ofEmptyPool(ipv4), retiredNode.hostname(),
                                 tester.asFlavor("default", NodeType.config), NodeType.config).build();
         var nodes = List.of(node);
         nodes = nodeRepository.nodes().addNodes(nodes, Agent.system);
diff --git a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/SpareCapacityMaintainerTest.java b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/SpareCapacityMaintainerTest.java
index da64fa2fd64..afdb88b22e1 100644
--- a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/SpareCapacityMaintainerTest.java
+++ b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/SpareCapacityMaintainerTest.java
@@ -36,8 +36,6 @@ import java.time.Instant;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Optional;
-import java.util.Set;
-import java.util.stream.Collectors;
 import java.util.stream.IntStream;
 
 import static org.junit.Assert.assertEquals;
@@ -328,11 +326,11 @@ public class SpareCapacityMaintainerTest {
         }
 
         private IP.Config ipConfig(int id, boolean host) {
-            return IP.Config.of(Set.of(String.format("%04X::%04X", id, 0)),
+            return IP.Config.of(List.of(String.format("%04X::%04X", id, 0)),
                                 host ? IntStream.range(0, 10)
                                                  .mapToObj(n -> String.format("%04X::%04X", id, n))
-                                                 .collect(Collectors.toSet())
-                                      : Set.of());
+                                                 .toList()
+                                      : List.of());
         }
 
         private void dumpState() {
diff --git a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/node/IPTest.java b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/node/IPTest.java
index ecf7697f781..1c513e78de1 100644
--- a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/node/IPTest.java
+++ b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/node/IPTest.java
@@ -1,7 +1,6 @@
 // Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.hosted.provision.node;
 
-import com.google.common.collect.ImmutableSet;
 import com.yahoo.config.provision.CloudName;
 import com.yahoo.config.provision.HostName;
 import com.yahoo.config.provision.NodeFlavors;
@@ -12,7 +11,7 @@ import com.yahoo.vespa.hosted.provision.provisioning.FlavorConfigBuilder;
 import com.yahoo.vespa.hosted.provision.testutils.MockNameResolver;
 import org.junit.Test;
 
-import java.util.LinkedHashSet;
+import java.util.ArrayList;
 import java.util.List;
 import java.util.Optional;
 import java.util.Set;
@@ -76,7 +75,7 @@ public class IPTest {
 
     @Test
     public void test_find_allocation_ipv6_only() {
-        IP.Pool pool = createNode(ImmutableSet.of(
+        IP.Pool pool = createNode(List.of(
                 "::1",
                 "::2",
                 "::3"
@@ -159,15 +158,15 @@ public class IPTest {
                 .addRecord("node1", "2600:1f10:::2")
                 .addRecord("node2", "2600:1f10:::3");
 
-        IP.Config config = IP.Config.of(Set.of("2600:1f10:::1"),
-                                        Set.of("2600:1f10:::2", "2600:1f10:::3"),
+        IP.Config config = IP.Config.of(List.of("2600:1f10:::1"),
+                                        List.of("2600:1f10:::2", "2600:1f10:::3"),
                                         List.of(HostName.of("node1"), HostName.of("node2")));
         IP.Pool pool = config.pool();
         Optional<IP.Allocation> allocation = pool.findAllocation(contextOf(true), emptyList);
     }
 
     private IP.Pool testPool(boolean dualStack) {
-        var addresses = new LinkedHashSet<String>();
+        var addresses = new ArrayList<String>();
         addresses.add("127.0.0.1");
         addresses.add("127.0.0.2");
         addresses.add("127.0.0.3");
@@ -202,8 +201,8 @@ public class IPTest {
         return pool;
     }
 
-    private static Node createNode(Set<String> ipAddresses) {
-        return Node.create("id1", IP.Config.of(Set.of("127.0.0.1"), ipAddresses),
+    private static Node createNode(List<String> ipAddresses) {
+        return Node.create("id1", IP.Config.of(List.of("127.0.0.1"), ipAddresses),
                            "host1", nodeFlavors.getFlavorOrThrow("default"), NodeType.host).build();
     }
 
diff --git a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/persistence/NodeSerializerTest.java b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/persistence/NodeSerializerTest.java
index 6e2d1e7fcd6..76cd9f0ec23 100644
--- a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/persistence/NodeSerializerTest.java
+++ b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/persistence/NodeSerializerTest.java
@@ -1,7 +1,6 @@
 // Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.hosted.provision.persistence;
 
-import com.google.common.collect.ImmutableSet;
 import com.yahoo.component.Version;
 import com.yahoo.component.Vtag;
 import com.yahoo.config.provision.ApplicationId;
@@ -42,7 +41,6 @@ import java.util.Arrays;
 import java.util.Collection;
 import java.util.List;
 import java.util.Optional;
-import java.util.Set;
 import java.util.stream.Collectors;
 
 import static com.yahoo.config.provision.NodeResources.Architecture;
@@ -251,7 +249,7 @@ public class NodeSerializerTest {
     @Test
     public void serialize_parent_hostname() {
         final String parentHostname = "parent.yahoo.com";
-        Node node = Node.create("myId", IP.Config.of(Set.of("127.0.0.1"), Set.of()), "myHostname", nodeFlavors.getFlavorOrThrow("default"), NodeType.tenant)
+        Node node = Node.create("myId", IP.Config.of(List.of("127.0.0.1"), List.of()), "myHostname", nodeFlavors.getFlavorOrThrow("default"), NodeType.tenant)
                 .parentHostname(parentHostname)
                 .build();
 
@@ -264,7 +262,7 @@ public class NodeSerializerTest {
     public void serializes_multiple_ip_addresses() {
         byte[] nodeWithMultipleIps = createNodeJson("node4.yahoo.tld", "127.0.0.4", "::4");
         Node deserializedNode = nodeSerializer.fromJson(nodeWithMultipleIps);
-        assertEquals(ImmutableSet.of("127.0.0.4", "::4"), deserializedNode.ipConfig().primary());
+        assertEquals(List.of("127.0.0.4", "::4"), deserializedNode.ipConfig().primary());
     }
 
     @Test
@@ -273,7 +271,7 @@ public class NodeSerializerTest {
 
         // Test round-trip with address pool
         node = node.with(node.ipConfig().withPool(IP.Pool.of(
-                Set.of("::1", "::2", "::3"),
+                List.of("::1", "::2", "::3"),
                 List.of(HostName.of("a"), HostName.of("b"), HostName.of("c")))));
         Node copy = nodeSerializer.fromJson(nodeSerializer.toJson(node));
         assertEquals(node.ipConfig(), copy.ipConfig());
@@ -536,7 +534,7 @@ public class NodeSerializerTest {
 
     private Node createNode() {
         return Node.create("myId",
-                           IP.Config.of(Set.of("127.0.0.1"), Set.of()),
+                           IP.Config.of(List.of("127.0.0.1"), List.of()),
                            "myHostname",
                            nodeFlavors.getFlavorOrThrow("default"),
                            NodeType.tenant).build();
diff --git a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/AllocationSimulator.java b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/AllocationSimulator.java
index 9a88b4664b0..12f5dd2a005 100644
--- a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/AllocationSimulator.java
+++ b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/AllocationSimulator.java
@@ -15,11 +15,8 @@ import com.yahoo.vespa.hosted.provision.node.IP;
 
 import javax.swing.JFrame;
 import java.util.ArrayList;
-import java.util.Collections;
-import java.util.HashSet;
 import java.util.List;
 import java.util.Optional;
-import java.util.Set;
 
 
 /**
@@ -77,17 +74,15 @@ public class AllocationSimulator {
         Node.Builder builder = Node.create("fake", hostname, flavor,
                 parent.isPresent() ? Node.State.ready : Node.State.active,
                 parent.isPresent() ? NodeType.tenant : NodeType.host)
-                .ipConfig(IP.Config.of(Set.of("127.0.0.1"), parent.isPresent() ? Set.of() : getAdditionalIP(), List.of()));
+                .ipConfig(IP.Config.of(List.of("127.0.0.1"), parent.isPresent() ? List.of() : getAdditionalIP(), List.of()));
         parent.ifPresent(builder::parentHostname);
         allocation(tenant, flavor).ifPresent(builder::allocation);
 
         return builder.build();
     }
 
-    private Set<String> getAdditionalIP() {
-        Set<String> h = new HashSet<String>();
-        Collections.addAll(h, "::1", "::2", "::3", "::4", "::5", "::6", "::7", "::8");
-        return h;
+    private List<String> getAdditionalIP() {
+        return List.of("::1", "::2", "::3", "::4", "::5", "::6", "::7", "::8");
     }
 
     private Optional<Allocation> allocation(Optional<String> tenant, Flavor flavor) {
diff --git a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/ContainerImagesTest.java b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/ContainerImagesTest.java
index 4537aaef45b..76b7b7e4bc7 100644
--- a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/ContainerImagesTest.java
+++ b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/ContainerImagesTest.java
@@ -12,8 +12,8 @@ import com.yahoo.vespa.hosted.provision.node.Allocation;
 import com.yahoo.vespa.hosted.provision.node.Generation;
 import org.junit.Test;
 
+import java.util.List;
 import java.util.Optional;
-import java.util.Set;
 
 import static org.junit.Assert.assertEquals;
 
@@ -71,7 +71,7 @@ public class ContainerImagesTest {
         if (gpu) {
             resources = resources.with(new NodeResources.GpuResources(1, 16));
         }
-        Node.Builder b = Node.reserve(Set.of("::1"), type + "1", "parent1", resources, type);
+        Node.Builder b = Node.reserve(List.of("::1"), type + "1", "parent1", resources, type);
         b.allocation(new Allocation(ApplicationId.defaultId(),
                                     ClusterMembership.from("container/id1/4/37",
                                                            Version.fromString("1.2.3"),
diff --git a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/DynamicAllocationTest.java b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/DynamicAllocationTest.java
index 7cf1b0d5177..a00a9b63d93 100644
--- a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/DynamicAllocationTest.java
+++ b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/DynamicAllocationTest.java
@@ -10,9 +10,9 @@ import com.yahoo.config.provision.ClusterSpec;
 import com.yahoo.config.provision.Environment;
 import com.yahoo.config.provision.Flavor;
 import com.yahoo.config.provision.HostSpec;
+import com.yahoo.config.provision.NodeAllocationException;
 import com.yahoo.config.provision.NodeResources;
 import com.yahoo.config.provision.NodeType;
-import com.yahoo.config.provision.NodeAllocationException;
 import com.yahoo.config.provision.ProvisionLock;
 import com.yahoo.config.provision.RegionName;
 import com.yahoo.config.provision.SystemName;
@@ -29,7 +29,6 @@ import com.yahoo.vespa.hosted.provision.node.IP;
 import org.junit.Test;
 
 import java.time.Instant;
-import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
@@ -341,8 +340,8 @@ public class DynamicAllocationTest {
         tester.activate(application, hosts);
 
         NodeList activeNodes = tester.nodeRepository().nodes().list().owner(application);
-        assertEquals(Set.of("127.0.127.2", "::2"), activeNodes.asList().get(1).ipConfig().primary());
-        assertEquals(Set.of("127.0.127.13", "::d"), activeNodes.asList().get(0).ipConfig().primary());
+        assertEquals(List.of("127.0.127.2", "::2"), activeNodes.asList().get(1).ipConfig().primary());
+        assertEquals(List.of("127.0.127.13", "::d"), activeNodes.asList().get(0).ipConfig().primary());
     }
 
     @Test
@@ -535,7 +534,7 @@ public class DynamicAllocationTest {
     }
 
     private void addAndAssignNode(ApplicationId id, String hostname, String parentHostname, ClusterSpec clusterSpec, NodeResources flavor, int index, ProvisioningTester tester) {
-        Node node1a = Node.create("open1", IP.Config.of(Set.of("127.0.233." + index), Set.of()), hostname,
+        Node node1a = Node.create("open1", IP.Config.ofEmptyPool("127.0.233." + index), hostname,
                                   new Flavor(flavor), NodeType.tenant).parentHostname(parentHostname).build();
         ClusterMembership clusterMembership1 = ClusterMembership.from(
                 clusterSpec.with(Optional.of(ClusterSpec.Group.from(0))), index); // Need to add group here so that group is serialized in node allocation
diff --git a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/DynamicProvisioningTest.java b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/DynamicProvisioningTest.java
index 54703b40781..eac0f7c7243 100644
--- a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/DynamicProvisioningTest.java
+++ b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/DynamicProvisioningTest.java
@@ -545,7 +545,8 @@ public class DynamicProvisioningTest {
         for (var host : hosts) {
             try (var nodeLock = nodeRepository.nodes().lockAndGetRequired(host.hostname())) {
                 var node = nodeLock.node();
-                nodeRepository.nodes().write(node.with(node.ipConfig().withPrimary(nodeRepository.nameResolver().resolveAll(node.hostname()))), nodeLock);
+                List<String> primary = List.copyOf(nodeRepository.nameResolver().resolveAll(node.hostname()));
+                nodeRepository.nodes().write(node.with(node.ipConfig().withPrimary(primary)), nodeLock);
             }
         }
     }
diff --git a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/DynamicProvisioningTester.java b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/DynamicProvisioningTester.java
index c982b195787..ebac6071a14 100644
--- a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/DynamicProvisioningTester.java
+++ b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/DynamicProvisioningTester.java
@@ -29,7 +29,6 @@ import com.yahoo.vespa.hosted.provision.testutils.InMemoryProvisionLogger;
 import java.time.Duration;
 import java.util.List;
 import java.util.Optional;
-import java.util.Set;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertTrue;
@@ -116,9 +115,9 @@ public class DynamicProvisioningTester {
 
     public void makeReady(String hostname) {
         Node node = nodeRepository().nodes().node(hostname).get();
-        provisioningTester.patchNode(node, (n) -> n.with(IP.Config.of(Set.of("::" + 0 + ":0"), Set.of())));
+        provisioningTester.patchNode(node, (n) -> n.with(IP.Config.ofEmptyPool("::" + 0 + ":0")));
         Node host = nodeRepository().nodes().node(node.parentHostname().get()).get();
-        host = host.with(IP.Config.of(Set.of("::" + 0 + ":0"), Set.of("::" + 0 + ":2")));
+        host = host.with(IP.Config.of(List.of("::" + 0 + ":0"), List.of("::" + 0 + ":2")));
         if (host.state() == Node.State.provisioned)
             provisioningTester.move(Node.State.ready, host);
     }
diff --git a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/HostCapacityTest.java b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/HostCapacityTest.java
index 35d6cdbf5d0..3a717ffade8 100644
--- a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/HostCapacityTest.java
+++ b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/HostCapacityTest.java
@@ -13,9 +13,7 @@ import org.junit.Before;
 import org.junit.Test;
 
 import java.util.ArrayList;
-import java.util.LinkedHashSet;
 import java.util.List;
-import java.util.Set;
 import java.util.stream.Stream;
 
 import static org.junit.Assert.assertEquals;
@@ -48,21 +46,21 @@ public class HostCapacityTest {
         NodeFlavors nodeFlavors = FlavorConfigBuilder.createDummies("host", "docker");
 
         // Create hosts
-        host1 = Node.create("host1", IP.Config.of(Set.of("::1"), createIps(2, 4), List.of()), "host1", nodeFlavors.getFlavorOrThrow("host"), NodeType.host).build();
-        host2 = Node.create("host2", IP.Config.of(Set.of("::11"), createIps(12, 3), List.of()), "host2", nodeFlavors.getFlavorOrThrow("host"), NodeType.host).build();
-        host3 = Node.create("host3", IP.Config.of(Set.of("::21"), createIps(22, 2), List.of()), "host3", nodeFlavors.getFlavorOrThrow("host"), NodeType.host).build();
-        host4 = Node.create("host3", IP.Config.of(Set.of("::21"), createIps(50, 0), List.of()), "host4", nodeFlavors.getFlavorOrThrow("host"), NodeType.host).build();
+        host1 = Node.create("host1", IP.Config.of(List.of("::1"), createIps(2, 4), List.of()), "host1", nodeFlavors.getFlavorOrThrow("host"), NodeType.host).build();
+        host2 = Node.create("host2", IP.Config.of(List.of("::11"), createIps(12, 3), List.of()), "host2", nodeFlavors.getFlavorOrThrow("host"), NodeType.host).build();
+        host3 = Node.create("host3", IP.Config.of(List.of("::21"), createIps(22, 2), List.of()), "host3", nodeFlavors.getFlavorOrThrow("host"), NodeType.host).build();
+        host4 = Node.create("host3", IP.Config.of(List.of("::21"), createIps(50, 0), List.of()), "host4", nodeFlavors.getFlavorOrThrow("host"), NodeType.host).build();
 
         // Add two containers to host1
-        var nodeA = Node.reserve(Set.of("::2"), "nodeA", "host1", resources0, NodeType.tenant).build();
-        var nodeB = Node.reserve(Set.of("::3"), "nodeB", "host1", resources0, NodeType.tenant).build();
+        var nodeA = Node.reserve(List.of("::2"), "nodeA", "host1", resources0, NodeType.tenant).build();
+        var nodeB = Node.reserve(List.of("::3"), "nodeB", "host1", resources0, NodeType.tenant).build();
 
         // Add two containers to host 2 (same as host 1)
-        var nodeC = Node.reserve(Set.of("::12"), "nodeC", "host2", resources0, NodeType.tenant).build();
-        var nodeD = Node.reserve(Set.of("::13"), "nodeD", "host2", resources0, NodeType.tenant).build();
+        var nodeC = Node.reserve(List.of("::12"), "nodeC", "host2", resources0, NodeType.tenant).build();
+        var nodeD = Node.reserve(List.of("::13"), "nodeD", "host2", resources0, NodeType.tenant).build();
 
         // Add a larger container to host3
-        var nodeE = Node.reserve(Set.of("::22"), "nodeE", "host3", resources1, NodeType.tenant).build();
+        var nodeE = Node.reserve(List.of("::22"), "nodeE", "host3", resources1, NodeType.tenant).build();
 
         // init host capacity
         nodes = new ArrayList<>(List.of(host1, host2, host3, nodeA, nodeB, nodeC, nodeD, nodeE));
@@ -81,7 +79,7 @@ public class HostCapacityTest {
         assertFalse(capacity.hasCapacity(host4, resources1)); // No IPs available
 
         // Add a new node to host1 to deplete the memory resource
-        Node nodeF = Node.reserve(Set.of("::6"), "nodeF", "host1", resources0, NodeType.tenant).build();
+        Node nodeF = Node.reserve(List.of("::6"), "nodeF", "host1", resources0, NodeType.tenant).build();
         nodes.add(nodeF);
         capacity = new HostCapacity(new LockedNodeList(nodes, () -> {}), hostResourcesCalculator);
         assertFalse(capacity.hasCapacity(host1, resources0));
@@ -133,9 +131,9 @@ public class HostCapacityTest {
 
     @Test
     public void verifyCapacityFromAddresses() {
-        Node nodeA = Node.reserve(Set.of("::2"), "nodeA", "host1", resources0, NodeType.tenant).build();
-        Node nodeB = Node.reserve(Set.of("::3"), "nodeB", "host1", resources0, NodeType.tenant).build();
-        Node nodeC = Node.reserve(Set.of("::4"), "nodeC", "host1", resources0, NodeType.tenant).build();
+        Node nodeA = Node.reserve(List.of("::2"), "nodeA", "host1", resources0, NodeType.tenant).build();
+        Node nodeB = Node.reserve(List.of("::3"), "nodeB", "host1", resources0, NodeType.tenant).build();
+        Node nodeC = Node.reserve(List.of("::4"), "nodeC", "host1", resources0, NodeType.tenant).build();
 
         // host1 is a host with resources = 7-100-120-5 (7 vcpus, 100G memory, 120G disk, and 5Gbps),
         // while nodeA-C have resources = resources0 = 1-30-20-1.5
@@ -180,7 +178,7 @@ public class HostCapacityTest {
                 "host",     // 7-100-120-5
                 "docker"); // 2- 40- 40-0.5 = resources1
 
-        return Node.create(hostHostname, IP.Config.of(Set.of("::1"), Set.of(), hostnames), hostHostname,
+        return Node.create(hostHostname, IP.Config.of(List.of("::1"), List.of(), hostnames), hostHostname,
                 nodeFlavors.getFlavorOrThrow("host"), NodeType.host).build();
     }
 
@@ -190,9 +188,9 @@ public class HostCapacityTest {
         return capacity.hasCapacity(host, requestedCapacity);
     }
 
-    private Set<String> createIps(int start, int count) {
+    private List<String> createIps(int start, int count) {
         // Allow 4 containers
-        Set<String> ipAddressPool = new LinkedHashSet<>();
+        var ipAddressPool = new ArrayList<String>();
         for (int i = start; i < (start + count); i++) {
             ipAddressPool.add("::" + i);
         }
diff --git a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/LoadBalancerProvisionerTest.java b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/LoadBalancerProvisionerTest.java
index cbe12a8202b..29277c7cea0 100644
--- a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/LoadBalancerProvisionerTest.java
+++ b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/LoadBalancerProvisionerTest.java
@@ -492,7 +492,7 @@ public class LoadBalancerProvisionerTest {
     private void assignIps(NodeList nodes) {
         try (var lock = tester.nodeRepository().nodes().lockUnallocated()) {
             for (int i = 0; i < nodes.size(); i++) {
-                tester.nodeRepository().nodes().write(nodes.asList().get(i).with(IP.Config.EMPTY.withPrimary(Set.of("127.0.0." + i))), lock);
+                tester.nodeRepository().nodes().write(nodes.asList().get(i).with(IP.Config.EMPTY.withPrimary(List.of("127.0.0." + i))), lock);
             }
         }
     }
diff --git a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/NodeCandidateTest.java b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/NodeCandidateTest.java
index c82b29c7d65..fac1111e616 100644
--- a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/NodeCandidateTest.java
+++ b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/NodeCandidateTest.java
@@ -12,7 +12,6 @@ import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
 import java.util.Optional;
-import java.util.Set;
 
 import static org.junit.Assert.assertEquals;
 
@@ -134,7 +133,7 @@ public class NodeCandidateTest {
 
     private static Node node(String hostname, Node.State state) {
         return Node.create(hostname, hostname, new Flavor(new NodeResources(2, 2, 2, 2)), state, NodeType.tenant)
-                .ipConfigWithEmptyPool(Set.of("::1")).build();
+                .ipConfigWithEmptyPool(List.of("::1")).build();
     }
 
     private static NodeCandidate node(String hostname,
@@ -144,9 +143,9 @@ public class NodeCandidateTest {
                                       boolean exclusiveSwitch) {
         Node node = Node.create(hostname, hostname, new Flavor(nodeResources), Node.State.ready, NodeType.tenant)
                 .parentHostname(hostname + "parent")
-                .ipConfigWithEmptyPool(Set.of("::1")).build();
+                .ipConfigWithEmptyPool(List.of("::1")).build();
         Node parent = Node.create(hostname + "parent", hostname, new Flavor(totalHostResources), Node.State.ready, NodeType.host)
-                          .ipConfig(IP.Config.of(Set.of("::1"), Set.of("::2")))
+                          .ipConfig(IP.Config.of(List.of("::1"), List.of("::2")))
                           .build();
         return new NodeCandidate.ConcreteNodeCandidate(node, false, totalHostResources.subtract(allocatedHostResources), Optional.of(parent),
                                                        false, exclusiveSwitch, false, true, false);
diff --git a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/ProvisioningTest.java b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/ProvisioningTest.java
index cb4644f179f..f0b47f04fb1 100644
--- a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/ProvisioningTest.java
+++ b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/ProvisioningTest.java
@@ -981,10 +981,10 @@ public class ProvisioningTest {
         // Add 2 config server hosts and 2 config servers
         Flavor flavor = tester.nodeRepository().flavors().getFlavorOrThrow("default");
         List<Node> nodes = List.of(
-                Node.create("cfghost1", IP.Config.of(Set.of("::1:0"), Set.of("::1:1")), "cfghost1", flavor, NodeType.confighost).build(),
-                Node.create("cfghost2", IP.Config.of(Set.of("::2:0"), Set.of("::2:1")), "cfghost2", flavor, NodeType.confighost).ipConfig(IP.Config.of(Set.of("::2:0"), Set.of("::2:1"), List.of())).build(),
-                Node.create("cfg1", IP.Config.of(Set.of("::1:1"), Set.of()), "cfg1", flavor, NodeType.config).parentHostname("cfghost1").build(),
-                Node.create("cfg2", IP.Config.of(Set.of("::2:1"), Set.of()), "cfg2", flavor, NodeType.config).parentHostname("cfghost2").build());
+                Node.create("cfghost1", IP.Config.of(List.of("::1:0"), List.of("::1:1")), "cfghost1", flavor, NodeType.confighost).build(),
+                Node.create("cfghost2", IP.Config.of(List.of("::2:0"), List.of("::2:1")), "cfghost2", flavor, NodeType.confighost).ipConfig(IP.Config.of(List.of("::2:0"), List.of("::2:1"), List.of())).build(),
+                Node.create("cfg1", IP.Config.of(List.of("::1:1"), List.of()), "cfg1", flavor, NodeType.config).parentHostname("cfghost1").build(),
+                Node.create("cfg2", IP.Config.of(List.of("::2:1"), List.of()), "cfg2", flavor, NodeType.config).parentHostname("cfghost2").build());
         tester.move(Node.State.ready, tester.nodeRepository().nodes().addNodes(nodes, Agent.system));
 
         InfraApplication cfgHostApp = new ConfigServerHostApplication();
diff --git a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/ProvisioningTester.java b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/ProvisioningTester.java
index be8c84141b5..6e78c4aa275 100644
--- a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/ProvisioningTester.java
+++ b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/ProvisioningTester.java
@@ -66,7 +66,6 @@ import java.util.ArrayList;
 import java.util.Collection;
 import java.util.HashSet;
 import java.util.Iterator;
-import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Optional;
 import java.util.Set;
@@ -212,7 +211,7 @@ public class ProvisioningTester {
             try (var lock = nodeRepository.nodes().lockAndGetRequired(prepared.hostname())) {
                 Node node = lock.node();
                 if (node.ipConfig().primary().isEmpty()) {
-                    node = node.with(IP.Config.of(Set.of("::" + 0 + ":0"), Set.of()));
+                    node = node.with(IP.Config.of(List.of("::" + 0 + ":0"), List.of()));
                     nodeRepository.nodes().write(node, lock);
                 }
                 if (node.parentHostname().isEmpty()) continue;
@@ -220,7 +219,7 @@ public class ProvisioningTester {
                 if (parent.state() == Node.State.active) continue;
                 NestedTransaction t = new NestedTransaction();
                 if (parent.ipConfig().primary().isEmpty())
-                    parent = parent.with(IP.Config.of(Set.of("::" + 0 + ":0"), Set.of("::" + 0 + ":2")));
+                    parent = parent.with(IP.Config.of(List.of("::" + 0 + ":0"), List.of("::" + 0 + ":2")));
                 nodeRepository.nodes().activate(List.of(parent), new ApplicationTransaction(new ProvisionLock(application, () -> { }), t));
                 t.commit();
             }
@@ -450,11 +449,11 @@ public class ProvisioningTester {
             String ipv6 = String.format("::%x", nextIP);
 
             nameResolver.addRecord(hostname, ipv4, ipv6);
-            HashSet<String> hostIps = new HashSet<>();
+            var hostIps = new ArrayList<String>();
             hostIps.add(ipv4);
             hostIps.add(ipv6);
 
-            Set<String> ipAddressPool = new LinkedHashSet<>();
+            var ipAddressPool = new ArrayList<String>();
             for (int poolIp = 1; poolIp <= ipAddressPoolSize; poolIp++) {
                 nextIP++;
                 String nodeHostname = hostnameParts[0] + "-" + poolIp + (hostnameParts.length > 1 ? "." + hostnameParts[1] : "");
@@ -485,7 +484,7 @@ public class ProvisioningTester {
             String ipv4 = "127.0.1." + i;
 
             nameResolver.addRecord(hostname, ipv4);
-            Node node = Node.create(hostname, IP.Config.of(Set.of(ipv4), Set.of()), hostname,
+            Node node = Node.create(hostname, IP.Config.of(List.of(ipv4), List.of()), hostname,
                                     nodeFlavors.getFlavorOrThrow(flavor), NodeType.config).build();
             nodes.add(node);
         }
@@ -553,7 +552,7 @@ public class ProvisioningTester {
         List<Node> nodes = new ArrayList<>(count);
         for (int i = startIndex; i < count + startIndex; i++) {
             String hostname = nodeNamer.apply(i);
-            IP.Config ipConfig = IP.Config.of(nodeRepository.nameResolver().resolveAll(hostname), Set.of());
+            IP.Config ipConfig = IP.Config.of(List.copyOf(nodeRepository.nameResolver().resolveAll(hostname)), List.of());
             Node node = Node.create("node-id", ipConfig, hostname, new Flavor(resources), nodeType)
                             .parentHostname(parentHostname)
                             .build();