ELK multiple NODE on 2 server

[PAQUIER_Christophe]

I want to join 2 nodes for Elasticsearch but i have an error

First node :
cluster.name : elk_spdc
node.name :elk1
node.data:true

network.host:192.168.1.61
network.publish_host:192.168.1.61
network.bind_host:192.168.1.61
transport.tcp.port:9300
http.port:9200

discovery.zen.ping.unicast.hosts:["192.168.1.61","192.168.1.62"]

second node :
cluster.name : elk_spdc
node.name :elk2
node.data:true

network.host:192.168.1.62
network.publish_host:192.168.1.62
network.bind_host:192.168.1.62
transport.tcp.port:9300
http.port:9200

discovery.zen.ping.unicast.hosts:["192.168.1.61","192.168.1.62"]

the 2 node start but i have an error
"[2018-02-01T16:32:28,663][INFO ][o.e.d.z.ZenDiscovery ] [elk2] failed to send join request to master [{elk1}{AluThBB6SsqQRikPYMNRPg}{ntdez45wROGrcFPrchO2MQ}{192.168.1.61}{192.168.1.61:9300}], reason [RemoteTransportException[[elk1][192.168.1.61:9300][internal:discovery/zen/join]]; nested: IllegalArgumentException[can't add node {elk2}{AluThBB6SsqQRikPYMNRPg}{BlM7ByEoS-e4-Z6bv1Kgug}{192.168.1.62}{192.168.1.62:9300}, found existing node {elk1}{AluThBB6SsqQRikPYMNRPg}{ntdez45wROGrcFPrchO2MQ}{192.168.1.61}{192.168.1.61:9300} with the same id but is a different node instance]; ]
"

I tried some different configuration but i can't joined 2 nodes.

Can you help me? I use elasticseach 6.6.1

[A_B]

You might have a rogue elasticsearch node running already that is called elk1. That would be the first I would check