[CentOS] CentOS6 - Break in attempt? What is the Exploit?

Mon Sep 21 18:42:55 UTC 2015
Gordon Messmer <gordon.messmer at gmail.com>

> > In other words, the
> >hostkeys would be identical.

I think what the error indicates is that a client tried to connect to 
SSH, and the host key there did not match the fingerprint in the 
client's "known_hosts" database.

> >It seems to me that someone attempted an ssh connection while spoofing
> >our internal address.  Is such a thing even possible? If so then how
> >does it work?

In the situation as you've described it, probably not.

It would be best to go to your logs themselves for the full log entry 
and context, rather than relying on a report that summarizes log entries.