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

**URL:** <https://discuss.elastic.co/t/warn-discovery-zen-ping-multicast-wolf-failed-to-send-multicast-ping-request-ioexception-operation-not-permitted/29174>\
**Category:** Elasticsearch\
**Created:** [September 12, 2015, 9:32am UTC](https://discuss.elastic.co/t/warn-discovery-zen-ping-multicast-wolf-failed-to-send-multicast-ping-request-ioexception-operation-not-permitted/29174 "2015-09-12T09:32:26Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![Wilson\_A\_Galafassi\_J](https://avatars.discourse-cdn.com/v4/letter/w/dc4da7/32.png) [@Wilson\_A\_Galafassi\_J](https://discuss.elastic.co/u/Wilson_A_Galafassi_J)\
**Post date:** [September 12, 2015, 9:32am UTC](https://discuss.elastic.co/t/warn-discovery-zen-ping-multicast-wolf-failed-to-send-multicast-ping-request-ioexception-operation-not-permitted/29174/1 "2015-09-12T09:32:26Z")

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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

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**Author:** ![dadoonet](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/dadoonet/32/137187_2.png) [@dadoonet](https://discuss.elastic.co/u/dadoonet)\
**Post date:** [September 12, 2015, 9:48am UTC](https://discuss.elastic.co/t/warn-discovery-zen-ping-multicast-wolf-failed-to-send-multicast-ping-request-ioexception-operation-not-permitted/29174/2 "2015-09-12T09:48:54Z")

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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.

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**Author:** ![Wilson\_A\_Galafassi\_J](https://avatars.discourse-cdn.com/v4/letter/w/dc4da7/32.png) [@Wilson\_A\_Galafassi\_J](https://discuss.elastic.co/u/Wilson_A_Galafassi_J)\
**Post date:** [September 12, 2015, 9:51pm UTC](https://discuss.elastic.co/t/warn-discovery-zen-ping-multicast-wolf-failed-to-send-multicast-ping-request-ioexception-operation-not-permitted/29174/3 "2015-09-12T21:51:09Z")

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

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**Author:** ![dadoonet](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/dadoonet/32/137187_2.png) [@dadoonet](https://discuss.elastic.co/u/dadoonet)\
**Post date:** [September 13, 2015, 12:40am UTC](https://discuss.elastic.co/t/warn-discovery-zen-ping-multicast-wolf-failed-to-send-multicast-ping-request-ioexception-operation-not-permitted/29174/4 "2015-09-13T00:40:05Z")

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[https://www.elastic.co/guide/en/elasticsearch/guide/current/\_important\_configuration\_changes.html#\_prefer\_unicast\_over\_multicast](https://www.elastic.co/guide/en/elasticsearch/guide/current/_important_configuration_changes.html#_prefer_unicast_over_multicast)

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**Author:** ![Wilson\_A\_Galafassi\_J](https://avatars.discourse-cdn.com/v4/letter/w/dc4da7/32.png) [@Wilson\_A\_Galafassi\_J](https://discuss.elastic.co/u/Wilson_A_Galafassi_J)\
**Post date:** [September 14, 2015, 1:11pm UTC](https://discuss.elastic.co/t/warn-discovery-zen-ping-multicast-wolf-failed-to-send-multicast-ping-request-ioexception-operation-not-permitted/29174/5 "2015-09-14T13:11:08Z")

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thanks.

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**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, 11:50pm UTC](https://discuss.elastic.co/t/warn-discovery-zen-ping-multicast-wolf-failed-to-send-multicast-ping-request-ioexception-operation-not-permitted/29174/6 "2017-07-05T23:50:27Z")

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