I am running a multi server setup with ISPConfig3;
Web Server (64bit)
Mail Server (64bit)
DNS Server 1 (64Bit)
DNS Server 2 (32Bit)
on Ubuntu 12.04 LTS.
Up until a few days ago everything worked as expected.
Then, two of the server DNS1 and DNS2 didn't know how to resolve to the Ubuntu Update Server while the other two (mail / web server) where able to connect and update / upgrade.
In the mean time the mail server has lost it too, simply can't resolve to the ubuntu servers, but knows how to get to other places.
Other than that, the do resolve and act as they should, except very slow in some instance. For example: ISPConfig3 Web Panel takes up to 5 Seconds or more to built the 1st screen. But afterwards is reasonably fast again.
I know for sure that there are Kernel updates since I just upgraded a 32 Bit server within my network, however has nothing to do with ISPConfig.
The Apt log file ends a few days ago on the DNS1 / DNS2 server and has no new conclusive entries.
I have absolutely nothing done manually that would lead me to think that I changed something to the worse.
It seems that one or more updates in the past simply caused the problem with the resolve.
Wish, they would do a little more research before release, wouldn't be the first time to get my system brain washed
Or, I just don't update anymore, also a shot into my own foot.
Also I noticed that the response from my server would become longer and longer during logon. I am logging in over the LAN using SSH and have Gigabit hardware.
This also would lead me to think thjat there is something with bind is not working right?
Is there anyone that may have gone the same path as I did and trustingly updated / upgrade and now sees the same behavior?
Just tried few other ways e.g. NSLOOKUP - The ubuntu update servers can be resolved this way.
Input is appreciated!