[PLUG] 4 minute and 44 seconds to send email because I bound an extra IP

[Mental <Mental@NeverLight.com>]

Forgive me for breaking the thread, but I only recently resubscribed.


I read this in the archives. 


The reason sendmail was hanging is because ip's are supposed to resolve.
Sendmail uses the resolved names internally.

Dig this:
sendmail -d0 < /dev/null
Version 8.12.0.Beta7
 Compiled with: LDAPMAP LOG MATCHGECOS MIME7TO8 MIME8TO7 NAMED_BIND
                NETINET NETUNIX NEWDB PIPELINING SASL SCANF STARTTLS
USERDB
                XDEBUG

============ SYSTEM IDENTITY (after readcf) ============
      (short domain name) $w = warpath
  (canonical domain name) $j = warpath.neverlight.com
         (subdomain name) $m = neverlight.com
              (node name) $k = warpath
========================================================

Sendmail resolves all of its locall names on startup.

Those names come from the IP (and sometimes a file). In general you want 
to have multihomed hosts have a name for each interface anyhow. Makes 
it easier to remember stuff.


I'd argue it further but really its semantic.

In your situation the 'right' thing to do is:
1. Do what you did and give the IP a name in /etc/hosts. 
or 
2. If you have a bunch of 'internal' ip's bound to your card, and they're
not going to be recieving mail anyhow, you should investigate the
confDONT_PROBE_INTERFACES configuration parameter. Its in
sendmail-{VERSION}/cf/README or on the web page.

It'll let you control what (if any) interfaces get their names inserted
into your {w} class.


Before this spirals into a 'dont use sendmail/my MTA is better'
discussion, I'd like to add a disclaimer that I'm only pointing out how to
fix the problem using the same tool, not discuss alternatives. 


Depending on what you're doing, a different MTA may very well be a better
solution for you. I just figured I'd explain what was going on.


On a side note, has anyone integrated kerberos authentication with 
sendmail? Just wondering what you're using for a backend.... I got the
SASL AUTH/STARTTLS encryption thing going on. 
 


--
Mental (Mental@NeverLight.com)

My girlfriend asked me how long I was going to be gone on this
tour.  I said, "the whole time."
--Steven Wright

GPG public key: http://www.neverlight.com/Mental.asc



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