Hi,
The entry in mail.log is the logical effect of someone knocking at the door
but not saying anything.
My resolv.conf and svc.conf are both correct (in svc.conf is
hosts=local,bind,yp)
As I mentioned nslookup succeeds very fast. However, it lasts a while before
a telnet to the host at port 25 results in the expected SMTP banner (when
the connecting hosts is not in /etc/hosts)
So there is that workaround (adding the ip&hostname to the hostfile) but I'm
stil wondering why the resolving for SMTP takes so much longer as a nslookup
on the commandline...
Regards,
Alex
-----Original Message-----
From: Alex Harkema
Sent: Wednesday, January 02, 2002 2:03 PM
To: 'tru64-unix-managers_at_ornl.gov'
Subject: smtp resolving hostname problem
Hi all,
First of all, I like to wish you all a happy new year! But with business now
being as usual again, I also have a question for you.
On an AS1200 running Tru64 v5.1 (patchkit 3) a couple of services is being
monitored from another host (by connecting the port)
To check whether SMTP is running is connects to the host at port 25, waits
for SMTP's answer header like the following:
Connected to host01.mydom.nl.
Escape character is '^]'.
220 host01.mydom.nl ESMTP Sendmail 8.9.3 (1.1.29.3/15Oct01-0139PM) Wed, 2
Jan 2002 13:29:34 +0100 (MET)
...and disconnects
In syslog.dated/current/mail.log I saw a lot of the following messages:
Jan 2 13:16:23 host01 sendmail[363262]: NOQUEUE: Null connection from
IDENT:root_at_[xxx.xx.xx.xxx]
With 'xxx.xx.xx.xxx' being the server running the monitoring tool its
ip-address.
Reason for the entries in mail.log is the timeout on the connect at port 25.
This sometimes happens. I guess the reason for that is, that host01 tries to
resolve the xxx.xx.xx.xxx hostname. (because he likes to know who's
knocking, right?)
Entries in resolv.conf are correct. Resolving the hostname on the command
line (nslookup) is always very fast. By adding the server's hostname in
/etc/hosts the timeout on the SMTP port no longer occurs.
Why does SMTP has a problem in resolving the hostname (while there is no
problem from the command line)
Besides adding the hostname in /etc/hosts, is there any other way to solve
this?
Thanks in advance for suggestions, hints etc.
Alex Harkema
Vertis unixbeheer
Received on Thu Jan 03 2002 - 09:04:15 NZDT