# Connectivity issues with a new/upgraded 2.X cluster? Read here first :) **URL:** \ **Category:** Elasticsearch\ **Created:** [November 27, 2015, 1:44am UTC](https://discuss.elastic.co/t/connectivity-issues-with-a-new-upgraded-2-x-cluster-read-here-first/35699 "2015-11-27T01:44:23Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![warkolm](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/warkolm/32/39224_2.png) [@warkolm](https://discuss.elastic.co/u/warkolm)\ **Post date:** [November 27, 2015, 1:44am UTC](https://discuss.elastic.co/t/connectivity-issues-with-a-new-upgraded-2-x-cluster-read-here-first/35699/1 "2015-11-27T01:44:24Z")
**If you are having issues with nodes not forming a cluster, or if you are unable to connect to a remote cluster, please read this first!** In Elasticsearch 2.0 we made some major changes to the way default networking is configured. The primary one is that Elasticsearch no longer listens to _all_ interfaces by default, and instead only binds to loopback/127.00.1. This means that if you are coming from 1.X you will need to explicitly set [`network.host`](https://www.elastic.co/guide/en/elasticsearch/reference/2.1/modules-network.html) in your `elasticsearch.yml` config file. The second is that multicast discovery has been removed as the default discovery method and is now available via a plugin only. For more information, please read the release notes, [here](https://www.elastic.co/guide/en/elasticsearch/reference/2.1/breaking_20_network_changes.html). ---
**Author:** ![warkolm](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/warkolm/32/39224_2.png) [@warkolm](https://discuss.elastic.co/u/warkolm)\ **Post date:** [November 27, 2015, 1:44am UTC](https://discuss.elastic.co/t/connectivity-issues-with-a-new-upgraded-2-x-cluster-read-here-first/35699/2 "2015-11-27T01:44:41Z")
---
**Author:** ![warkolm](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/warkolm/32/39224_2.png) [@warkolm](https://discuss.elastic.co/u/warkolm)\ **Post date:** [January 8, 2016, 4:57am UTC](https://discuss.elastic.co/t/connectivity-issues-with-a-new-upgraded-2-x-cluster-read-here-first/35699/3 "2016-01-08T04:57:32Z")
---
**Author:** ![riki](https://avatars.discourse-cdn.com/v4/letter/r/c4cdca/32.png) [@riki](https://discuss.elastic.co/u/riki)\ **Post date:** [January 23, 2016, 9:08pm UTC](https://discuss.elastic.co/t/connectivity-issues-with-a-new-upgraded-2-x-cluster-read-here-first/35699/4 "2016-01-23T21:08:25Z")
Hi, I started using ES 2.0. In elasticsearch.yml file I have set network.host as _host name_. I see lots of exception as below: > [2016-01-23 09:01:02,388][WARN][cluster.service] [Mangle] failed to reconnect to node {Gee}{MtDkhr9rSza5QoSqKTqkrA}{127.0.0.1}{127.0.0.1:9303}{data=false, client=true} > ConnectTransportException[[Gee][127.0.0.1:9303] connect\_timeout[30s]]; nested: ConnectException[Connection refused: no further information: /127.0.0.1:9303]; > at org.elasticsearch.transport.netty.NettyTransport.connectToChannels(NettyTransport.java:922) > at org.elasticsearch.transport.netty.NettyTransport.connectToNode(NettyTransport.java:855) > at org.elasticsearch.transport.netty.NettyTransport.connectToNode(NettyTransport.java:828) > at org.elasticsearch.transport.TransportService.connectToNode(TransportService.java:243) > at org.elasticsearch.cluster.service.InternalClusterService$ReconnectToNodes.run(InternalClusterService.java:598) > at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) > at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) > at java.lang.Thread.run(Thread.java:745) > Caused by: java.net.ConnectException: Connection refused: no further information: /127.0.0.1:9303 > at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method) > at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:717) > at org.jboss.netty.channel.socket.nio.NioClientBoss.connect(NioClientBoss.java:152) > at org.jboss.netty.channel.socket.nio.NioClientBoss.processSelectedKeys(NioClientBoss.java:105) > at org.jboss.netty.channel.socket.nio.NioClientBoss.process(NioClientBoss.java:79) > at org.jboss.netty.channel.socket.nio.AbstractNioSelector.run(AbstractNioSelector.java:337) > at org.jboss.netty.channel.socket.nio.NioClientBoss.run(NioClientBoss.java:42) > at org.jboss.netty.util.ThreadRenamingRunnable.run(ThreadRenamingRunnable.java:108) > at org.jboss.netty.util.internal.DeadLockProofWorker$1.run(DeadLockProofWorker.java:42) > ... 3 more I am not sure why transport client is still trying to connect to 127.0.0.1 even after setting network.host. I also tried setting transport.host as host name but no luck. What am I doing wrong? Thanks. ---
**Author:** ![warkolm](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/warkolm/32/39224_2.png) [@warkolm](https://discuss.elastic.co/u/warkolm)\ **Post date:** [January 24, 2016, 2:04am UTC](https://discuss.elastic.co/t/connectivity-issues-with-a-new-upgraded-2-x-cluster-read-here-first/35699/5 "2016-01-24T02:04:51Z")
It'd help if you provided the relevant config sections. ---
**Author:** ![riki](https://avatars.discourse-cdn.com/v4/letter/r/c4cdca/32.png) [@riki](https://discuss.elastic.co/u/riki)\ **Post date:** [January 24, 2016, 3:07am UTC](https://discuss.elastic.co/t/connectivity-issues-with-a-new-upgraded-2-x-cluster-read-here-first/35699/6 "2016-01-24T03:07:59Z")
Hi Mark, Here is the settings that I have put in elasticsearch.yml. > cluster.name: TESTCLUSTER > network.bind\_host: [es-node.test.com](http://es-node.test.com) > network.publish\_host: [es-node.test.com](http://es-node.test.com) > transport.tcp.port: 9300 > http.port: 9200 > http.enabled: false > discovery.zen.ping.multicast.enabled: false > discovery.zen.ping.unicast.hosts: [master-node.test.com:9300](http://master-node.test.com:9300) > index.fielddata.cache: node > indices.fielddata.cache.size: 1m > indices.cache.filter.size: 1m > threadpool.bulk.type: fixed > threadpool.bulk.queue\_size: 8000 In log i see the following while starting up > [2016-01-23 08:52:59,603][INFO][node] [Mangle] version[2.0.0], pid[1844], build[de54438/2015-10-22T08:09:48Z] > [2016-01-23 08:52:59,605][INFO][node] [Mangle] initializing ... > [2016-01-23 08:52:59,942][INFO][plugins] [Mangle] loaded , sites > [2016-01-23 08:53:00,337][INFO][env] [Mangle] using [1] data paths, mounts [[(C:)]], net usable\_space [82.1gb], net total\_space [99.6gb], spins? [unknown], types [NTFS] > [2016-01-23 08:53:08,744][INFO][node] [Mangle] initialized > [2016-01-23 08:53:08,745][INFO][node] [Mangle] starting ... > [2016-01-23 08:53:09,702][INFO][transport] [Mangle] publish\_address {[es-node.test.com/10.135.20.24:9300](http://es-node.test.com/10.135.20.24:9300)}, bound\_addresses {10.135.20.24:9300} > [2016-01-23 08:53:09,744][INFO][discovery] [Mangle] TESTCLUSTER/CYoSCFfaRMSPvb9zvn0KCw > [2016-01-23 08:53:19,141][INFO][cluster.service] [Mangle] detected\_master {Ankhi}{SEMYv5YIQQ27KQMywDxcjQ}{10.135.20.45}{10.135.20.45:9300}, added {{Laura Dean}{bme0NfOERmC4qkRz4PEt3A}{127.0.0.1}{127.0.0.1:9301}{data=false, client=true},{Air-Walker}{kGeX3KnXSG2Mqv7shVeKGQ}{10.129.152.151}{10.129.152.151:9300},{Gee}{MtDkhr9rSza5QoSqKTqkrA}{127.0.0.1}{127.0.0.1:9303}{data=false, client=true},{Fault Zone}{Girj3ldxQgacdj-SHNim6w}{127.0.0.1}{127.0.0.1:9302}{data=false, client=true},{Ankhi}{SEMYv5YIQQ27KQMywDxcjQ}{10.135.20.45}{10.135.20.45:9300},}, reason: zen-disco-receive(from master [{Ankhi}{SEMYv5YIQQ27KQMywDxcjQ}{10.135.20.45}{10.135.20.45:9300}]) > [2016-01-23 08:53:20,315][WARN][cluster.service] [Mangle] failed to connect to node [{Gee}{MtDkhr9rSza5QoSqKTqkrA}{127.0.0.1}{127.0.0.1:9303}{data=false, client=true}] Thanks. ---
**Author:** ![warkolm](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/warkolm/32/39224_2.png) [@warkolm](https://discuss.elastic.co/u/warkolm)\ **Post date:** [January 24, 2016, 3:31am UTC](https://discuss.elastic.co/t/connectivity-issues-with-a-new-upgraded-2-x-cluster-read-here-first/35699/7 "2016-01-24T03:31:50Z")
Well it's connecting to a valid interface. I'd suggest you create a separate thread and ask, I don't think this is a settings issue related to the original post. ---
**Author:** ![Python\_Coder](https://avatars.discourse-cdn.com/v4/letter/p/aeb1de/32.png) [@Python\_Coder](https://discuss.elastic.co/u/Python_Coder)\ **Post date:** [February 21, 2016, 11:22am UTC](https://discuss.elastic.co/t/connectivity-issues-with-a-new-upgraded-2-x-cluster-read-here-first/35699/8 "2016-02-21T11:22:51Z")
are you sure that the host resolution evaluates to the Non-loopback IP address on node Gee? ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [July 5, 2017, 11:14pm UTC](https://discuss.elastic.co/t/connectivity-issues-with-a-new-upgraded-2-x-cluster-read-here-first/35699/9 "2017-07-05T23:14:38Z")