DNS lookup problems specific the Facebook domains

[JINMEI Tatuya / 神明達哉]

At Fri, 21 Nov 2008 10:47:42 -0800,
Rob Tanner <rtanner at linfield.edu> wrote:

> I'm trying to figure out if this is my problem or a Facebook problem.  
> The first issue was with facebookmail.com.  The cache entry would become 
> corrupt and I would have to clear cache to get things back to working 
> again.  Since facebookmail.com resolves to a single IP address, my work 
> around was to make my internal DNS authoritative for it and the problem 
> went away.
> 
> A week ago, DNS lookups for  facebook.com failed completely.  Even 
> restarting the DNS  service didn't fix the problem.  Currently, and as a 
> temporary fix only, I am forwarding facebook,com lookups to an 
> off-campus server which does not seem to have the problem.  And now, as 
> of last night, lookups to fbcdn.net (which apparently hosts stylesheets) 
> fail completely and I've implemented the same forwarding scheme there as 
> well.  I've been tracking resource allocations on the Linux box that 
> hosts the DNS just to see if there might be some connection there, and 
> as far as I can tell, there isn't anything there that might explain it.
> 
> Being that we are a four year residential college, the heaviest hit on 
> our DNS servers are students, and Facebook is the singularly most 
> heavily used external service.  Also, as far as I can tell, we are 
> having no problems looking up any other addresses.  Has anyone else seen 
> this problem with Facebook or does this problem sound familiar with any 
> other sites.  I'm baffled and any ideas about what to look for would be 
> most appreciatd.

Does this still happen?  If so, and if you're using BIND 9.5.x prior
to 9.5.1b3, I'd suggest you upgrade to 9.5.1b3.  Prior versions of 9.5
have a bug in cache management that could cause failure of name
resolution for particular domain names.

---
JINMEI, Tatuya
Internet Systems Consortium, Inc.