nanog mailing list archives

Re: Memory leak cause of Comcast DNS problems


From: Florian Weimer <fw () deneb enyo de>
Date: Sun, 17 Apr 2005 18:29:27 +0200


* Sean Donelan:

Perhaps your DNS software also has a memory leak?  Anyone know which
software Comcast was using?  Should other ISPs be concerned they might
have the same latent problem in their systems?

Probably yes, especially if they don't read documentation of their DNS
software.

| The maximum amount of memory to use for the server's cache, in
| bytes. [...] The default is unlimited, meaning that records are
| purged from the cache only when their TTLs expire.

The number of complaints I've heard that "DNS resolvers eat *so* much
memory" suggests that few people tweak the default configuration. 8-(

However, it's unlikely that this was the cause of Comcast's problems
because DNS cache overflows would have an impact on a much larger
scale.


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