Elasticsearch 2.1 network settings

I just installed elasticsearch 2.1, and from the log, it shows it's using while version 1.7 it's bounded to actual IP address.
[INFO ][transport] publish_address {}, bound_addresses {}, {[::1]:9300}
[INFO ][http] publish_address {}, bound_addresses {}, {[::1]:9200}

with this change, the indexer faced connection problem if i configure the hosts as server name or server actual IP address. It worked if i use (I didn't check if localhost works).
From the network document, it looks to me this is expected. Did I get this correctly?

And there is a warning message in the log, what does this mean? and how to fix it?
[2015-11-26 14:20:06,191][WARN ][bootstrap ] unable to install syscall filter: prctl(PR_GET_NO_NEW_PRIVS): Invalid argument

Read over https://www.elastic.co/guide/en/elasticsearch/reference/2.1/breaking_20_network_changes.html#_bind_to_localhost

Thank you. How about the warning? what does it mean?

Not sure sorry.

This can be ignored and does not harm ES.

The ES team opened a playground to fiddle with Linux syscalls to minimize ES process privileges at bootstrap time, some of the calls may succeed, some may fail.

noted, thank you all for the clarification :slight_smile: