# Master not discovered exception **URL:** \ **Category:** Elasticsearch\ **Created:** [April 11, 2017, 7:08am UTC](https://discuss.elastic.co/t/master-not-discovered-exception/81923 "2017-04-11T07:08:53Z")\ **Posts on this page:** 1\ **Showing post:** 9
**Author:** ![techpanga](https://avatars.discourse-cdn.com/v4/letter/t/3ab097/32.png) [@techpanga](https://discuss.elastic.co/u/techpanga)\ **Post date:** [May 20, 2017, 8:16pm UTC](https://discuss.elastic.co/t/master-not-discovered-exception/81923/9 "2017-05-20T20:16:31Z")
Hi My case is similar but no issues with firewall. Here are details... > [@ElasticSearch 5.4 Nodes unable to join cluster - Troubleshooting](https://discuss.elastic.co/t/elasticsearch-5-4-nodes-unable-to-join-cluster-troubleshooting/86536): > > Hi There, We are running into some issues post upgrade from 2.3.x to 5.4. OS : RHEL 7 Java : JDK1.8.0\_111 Server (VM) #1: node.name: node-1 network.host: xxx.xxx.197.14 cluster.name: dsinke3 node.master: true node.data: true path.data: /elkstore/elasticsearch path.logs: /elkstore/logs bootstrap.memory\_lock: true discovery.zen.ping.unicast.hosts: ["xxx.xxx.197.14:9200", "xxx.xxx.197.15:9200", "xxx.xxx.197.16:9200", "xxx.xxx.197.17:9200", "xxx.xxx.197.18:9200"] discovery.zen.minimum\_master\_n… -Regards, dp --- _[View the full topic](https://discuss.elastic.co/t/master-not-discovered-exception/81923)._