[WARN ][discovery.zen.ping.multicast] [Wolf] failed to send multicast ping request: IOException[Operation not permitted]

HI,

In my elasticsearch.log i have this error when start.[WARN ][discovery.zen.ping.multicast] [Wolf] failed to send multicast ping request: IOException[Operation not permitted]

I'm using Centos 6 on EC2 + jdk1.8.0_60 + elasticsearch version 1.7.1

Thanks,
Wilson

Sounds like your OS or Network does not allow multicast.
Whatever, it is a bad practice for production and you should use unicast.
It will be the default in 2.0 and multicast will be a plugin.

So... i have to change something in elasticsearch config to work in unicast mode?

https://www.elastic.co/guide/en/elasticsearch/guide/current/_important_configuration_changes.html#_prefer_unicast_over_multicast

thanks.