I'm receiving the wonderful "The authenticity of host xx can't be established." message when attempting to SSH into a box. I have two systems that recently swapped names. My system is a RHEL5.6 box.
System X with IP xx
System Y with IP yy
Changed to System X with IP yy, system Y with IP xx.
(hope that's easy enough to explain what we did)
I removed both systems from my .ssh/known_hosts file (and verified neither IP is listed anywhere), but when I SSH into one of them, it still shows the IP of the original name. The other system works no problem, but it appears that there is a cache somewhere that still has the old information.
I've completely cleared the known_hosts file, as well as rebooted the system, in an attempt to clear the problem, but with no luck.
Any ideas? I'm stumped! This is only happening on my system, nobody else has a problem.
Update: I had already removed the offending keys from the file. I had also completely erased the known_hosts file. It still happens. there is nothing different in the configuration of the .ssh than any other account. And if it was an error in the .ssh files, it would affect other ssh connections as well. But the other system that had swapped names with this one, does NOT give this problem. it works correctly. It is only one of the two systems having the problem. The box has been reloaded twice since this change as well. So I know it's not the server itself.
I found out that my coworker is also having the same issue now, with the same box. And only this one box.
So if our DNS zone files are correct, where could this possibly be coming from? Neither system involved in this change has the old information in it. our DNS looks clean. Our accounts do not reference the old info. tracert shows the old IP with the name, as does ping, and then ssh. But an nslookup using forward or reverse comes back correct. Kinda frustrating.