WOW! ... weird

[Roy Arends]

On Sat, 7 Apr 2001, Ryan Crouch wrote:

> VERY odd behaviour, I smell UFO's
> 
> I have run BIND nameservers for 4 years now, and I have never seen what I
> saw yesterday.
> 
> The nameservers in question yesterday hosted 600+ domains. All of a sudden
> the name resolution stopped, and it was instaneous. There was no
> modification of named.conf's or zone files. The servers simply didn't even
> attempt to resolve. I killed NS2's zone files and restarted it to init the
> transfer. That happened without a problem. NS2 started to work flakily but
> would take minutes to resolve hosts. NS1, was a nightmare. I removed,
> zone's, restored named.conf's from old backups, made a cacheing only
> configuration, rebuilt BIND from source code, restored old binarys. Nothing
> happened. The machine simply used 100% CPU. All of a sudden, it started
> working, without a problem. I added forwarders to the configuration and boom
> .... it started using 100% again. Took the forwarders out, and there wasn't a
> problem. When I went back to NS2 during the rebuild of ns1 ... it was
> working fine.
> 
> 2 Hours later, it was all ok.
> 
> Funny though, the CPU utilization of our Cisco Core router jumped 17
> percent, and a frame relay downstream client's traffic jumped from 15kbit,
> to 1.6mbit.
> 
> Any Ideas on that ? If none thats ok, just letting you know what a fun day I
> had ;)

Which OS ?
Which Nameserver ?
Which version of the nameserver ?
Config ?
Logs ?
DNS architecture ?

We might be able to give you Any Ideas on that.

Regards,
Roy Arends
Nominum