Hostname Lookup Delay and Timeout

[Jim Levie]

On Mon, 2004-04-12 at 14:41, Jeremy Fisher wrote:
>
> So, for example, the outside client is attempting to
> connect to the IMAP, POP, or SMTP services and my
> server is then (apparently) attempting to resolve a
> hostname based on the IP address of the client. There
> is no hostname available, but my server still takes
> its 10-15 minutes to figure this out. What I want is
> to prevent Sendmail and/or Cyrus from bothering with
> seeking out a hostname for a client -- given the
> nature of my virtual host environment, it's
> information that isn't crucial to authentication or
> anything else, so far as I know!
> 
10-15 minutes sounds way too long for a DNS problem, unless the DNS for
the client's IP is exceptionally slow to respond. I'd expect a DNS time
out to be on the order of 1-2 minutes.

You can check to see if a reverse lookup is really taking that long by
getting the client's IP from your cyrus log and executing 'host
client-IP' in a shell. If you find that taking 10-15 minutes I'd suggest
trying the same thing from some other Internet host to see if the
problem is at your end or at the client's end.
-- 
Jim Levie <jim at entrophy-free.net>

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