I have a Graylog server that is showing IP addresses for 2 servers instead of Hostnames. It is showing the correct hostnames for the other servers. I have already confirmed DNS is correct. Any ideas on why GL would show IP instead of host name?
I figured out the issue. It was a matter of creating reverse lookup entries in DNS. Originally I only set forward lookup entries. Then delete the host in Graylog and restart rsync. Then you can issue logger -p user.err to create a log. Hope that helps.