This is a summary to a question which I did not actually submit to the Alpha
Managers list, but some of you may be interested in hearing the answer anyhow.
It appears that with the upgrade to 4.0D, the MTU on our FDDI interface was
raised to something over 4000. This caused outgoing mail from sendmail to fail
to many remote sites, including msn.com, concentric.net, utoledo.edu, and
colorado.edu. The failure looked like a timeout during transmission, and the
error message was "Read error" from the remote site. It looked like the remote
site was not recognizing the "dot on a line by itself" to end the DATA
transmission. When I changed the MTU back to 1500, the mail started going
through fine.
So if your mailserver's primary interface is FDDI and you are seeing problems
with outgoing sendmail, you might try changing the MTU back to 1500. You can
do it by hand:
ifconfig faa0 ipmtu 1500
And if that works then in the /etc/rc.config:
IFCONFIG_0="x.x.x.x netmask x.x.x.x broadcast x.x.x.x ipmtu 1500"
Hope this saves someone the time and effort I have gone through to solve this,
the MTU was the last thing I would have even considered.
--Sheila
--
Sheila Hollenbaugh Sr. Computer System Administrator (O-)
Wright State University College of Engineering & Computer Science
Dayton, OH 45435 http://www.cs.wright.edu/people/staff/shollen/
shollen_at_cs.wright.edu Voice: (937) 775-5077 FAX: (937) 775-5009
Received on Thu Oct 01 1998 - 14:50:02 NZST