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[LDM #RVC-520134]: Reverse DNS Lookup Oddity

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  • Subject: [LDM #RVC-520134]: Reverse DNS Lookup Oddity
  • Date: Tue, 30 Jan 2018 09:40:36 -0700
Robert,

> I hope to be able to talk to our systems folks on Tuesday,

Please let us know what your system administrators think.

> but after looking around, I can make a few observations...
> 
> 1) Our host.conf file on the upstream server is simply "multi on".  There is 
> no "order" statement.  This file hasn't been changed since 2013.

Probably OK, then.

> 2) We do not appear to run the "named" service, though we do have a pair of 
> name servers listed in /etc/resolv.conf.

If named(8) isn't running on the local system, then you'll need other name 
servers specified in "/etc/resolv.conf".

> All that said, we have two downstream servers that are connected to the one 
> upstream server, one resolves correctly and the other does not (from the 
> standpoint of the upstream server).  For the life of me, I don't see any 
> configuration differences between any of these servers.  The only difference 
> is that the one downstream LDM server was patched and rebooted.  Perhaps the 
> reboot exposed some latent DNS issue that was only made apparent after a new 
> ldmd process was spawned.  The ldmd process to the other "recognized" server 
> was established months ago.  I do know that DNS changes were made in 
> mid-October.  I'm curious what would happen if I restarted LDM on that 
> downstream server that is still recognized...

I suspect that if you restart the recognized downstream system, then it will 
have the same problem.

> I'll see what our admins have to say about our DNS setup and let you know if 
> this turns on any light bulbs.

Please do.

Regards,
Steve Emmerson

Ticket Details
===================
Ticket ID: RVC-520134
Department: Support LDM
Priority: Normal
Status: Closed
===================
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