08-25-2011 08:26 AM - edited 03-04-2019 01:24 PM
About a month ago I upgraded our AD/Exchange Server. The old internal IP was 10.1.1.95, the new one was 10.1.1.96. No DNS change was needed at our registrar as I just changed the NAT to point to the new address (the public IP is 64.124.160.95.)
A week or so ago I upgraded our entire Ubuntu linux stack from 9.10 to 10.4, and since then mail.DOMAIN.com has been resolving to 10.1.1.95 internally. Externally it still goes to the public IP so that is fine.
I have made a bunch of configuration changes on the servers themselves and nothing seems to be working - someone pointed out to me that our Cisco equipment could have something to do with it.
I am a complete novice - I know how to change configuration and whatnot but I am no network engineer. I had heard that it could be DNS doctoring, and I went here
http://www.cisco.com/en/US/products/ps6120/products_configuration_example09186a00807968c8.shtml but that didn't seem to be the issue, I have no entries denoted with the "dns" that it says is needed for the rewrite.
Equipment:
Cisco PIX 515 Firewall, Software Version 7.0(1), Device Manager Version 5.0(1)
Cisco C2970 Switch Version 12.2(25)SEB2, Release software (fc1)
Cisco C2900 Router, Version 15.0(1)M1, Release software (fc1)
My NAT rule for our mail server:
static (inside,outside) 64.124.160.95 10.1.1.96 netmask 255.255.255.255
Does anyone have any ideas of what it could be?
08-25-2011 08:29 AM
I highly doubt it's your network equipment since they don't provide name resolution. On the Ubuntu box, do you have entries in your hosts file? If you put one in for the mail server does it work?
08-25-2011 08:37 AM
Collin,
I also do not believe it is the networking equipment - I am trying to explore all avenues.
I have already tried putting mail.DOMAIN.com to 10.1.1.96 in /etc/hosts - it still resolves it to 10.1.1.95.
08-25-2011 08:53 AM
Issue turned out to be an alias definition on the PIX firewall. I told you I was a novice
Thanks for the help!!
I'm trying to figure out how to note this as resolved...
08-25-2011 09:03 AM
Glad to hear it's working.
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