Question about messares log

["Luis Cova" <lcova poz unexpo edu ve>]

Hello,, i would like to know what does these messages mean....
and what do i have to do to fix them


Feb 28 09:53:13 anakin named[334]: sysquery: findns error (NXDOMAIN) on
anakin.poz.unexpo.edu.ve.0.0.127.in-addr.arpa?

Feb 28 09:54:00 anakin named[334]: unapproved update from
[150.187.181.100].3186 for poz.unexpo.edu.ve

Feb 28 09:56:16 anakin named[334]: unapproved update from
[150.187.181.100].3220 for 181.187.150.in-addr.arpa

Feb 28 09:56:01 anakin named[334]: unrelated additional info
'G.ROOT-SERVERS.NET' type A from [150.187.117.2].53

Feb 28 09:56:32 anakin named[334]: bad referral (. !< com)

Feb 28 09:56:01 anakin named[334]: bad referral (. !< NET)

Feb 28 10:09:07 anakin PAM_pwdb[859]: auth could not identify password for
[root]