After use Shield, the ES cluster do not work

I am using the ES 2.1.1 with Shield 2.1.1. My cluster included two node "wisesearch-node1" and "wisesearch-node2", it had worked fine until I installed Shield plugin.

After installed Shield plugin, both node1 and node2 are not success launch. the node1 will get "[wisesearch-node1] failed to send join request to master" error. And the other hand, the node2 will get " No route to host" error. Please look at log:

Node1's log:
[2016-04-11 17:35:05,870][INFO ][discovery.zen ] [wisesearch-node1] failed to send join request to master [{wisesearch-node2}{WSGMaGHSQEyrHZmONb8J6w}{}{}], reason [RemoteTransportException[[wisesearch-node2][][internal:discovery/zen/join]]; nested: ConnectTransportException[[wisesearch-node1][] connect_timeout[30s]]; nested: NotSerializableExceptionWrapper[No route to host]; ]

Node2's log:
[2016-04-11 17:35:37,562][WARN ][shield.transport.netty ] [wisesearch-node2] exception caught on transport layer [[id: 0x14feb6ff]], closing connection No route to host
at Method)

The Node1's config: wisesearch wisesearch-node1 [""]
discovery.zen.minimum_master_nodes: 2
shield.audit.enabled: true

The Node2's config: wisesearch wisesearch-node2 [""]
discovery.zen.minimum_master_nodes: 2
shield.audit.enabled: true

Please help to look at this issue, thanks!

This is a networking issue, not an ES one.
You should check you can ping the nodes and that nodes can ping each other.

Hi warkolm, I confirm that the nodes can ping each other, the cluster works fine before I install Shield plugin.

Yes, you are right. After I disabled firewall from node1, the cluster could works right again.

Thanks for your advice!