[TEST] Make it clear what address we try to bind

core/src/test/java/org/elasticsearch/test/discovery/ClusterDiscoveryConfiguration.java

@@ -150,8 +150,7 @@ public class ClusterDiscoveryConfiguration extends SettingsSource {
                     try (ServerSocket serverSocket = new ServerSocket()) {
                         // Set SO_REUSEADDR as we may bind here and not be able to reuse the address immediately without it.
                         serverSocket.setReuseAddress(NetworkUtils.defaultReuseAddress());
-                        serverSocket.bind(new InetSocketAddress(nextPort));
-
+                        serverSocket.bind(new InetSocketAddress("127.0.0.1", nextPort));
                         // bind was a success
                         foundPortInRange = true;
                         unicastHostPorts[i] = nextPort;