On 03/10/2011 01:00 AM, Adam N. Copeland wrote:
Seeing a problem with inbound delivery from relays. Incoming client
connections are timing out, but I'm able to telnet to port 25 on my host
and immediately get the 220 banner every time. Sometimes the connection
times out before the 220 banner is displayed, sometimes it doesn't and
the client never sends a HELO/EHLO. This is only happening to *specific*
clients. The majority of clients are able to deliver mail with no
problems. Sometimes there is a 421 error, sometimes it just throws
"timeout after CONNECT from unknown".
Version is 2.5.4, and I've disabled all of my client restrictions
including a check_policy_service IP Blocker.
In the debug output below, you can see how one client gets the 220
banner, and the other doesn't, but the result is the same, a 421.
Digging deeper, a packet capture shows that there is an EHLO from the
client, but it appears to come before the 220 sometimes.
debug output follows, then snoop, then postconf -n is at the bottom.
Many thanks
Debug output:
Please, don't post DEBUG output unless requested to do so.
It often doesn't help, especially before it is clear postfix is in the
wrong.
Mar 9 18:38:03 pmx4 postfix/smtpd[13358]: [ID 197553 mail.info] connect
from unknown[134.53.6.74]
okay
Mar 9 18:41:03 pmx4 postfix/smtpd[13243]: [ID 197553 mail.info]>
unknown[134.53.6.74]: 421 4.4.2 smtp-in.montclair.edu Error: timeout
exceeded
That's 3 minutes (180 seconds); any particular reason you changed it
from the default of 300 seconds ?
Mar 9 18:41:03 pmx4 postfix/smtpd[13243]: [ID 197553 mail.info] timeout
after CONNECT from unknown[134.53.6.74]
Mar 9 18:41:03 pmx4 postfix/smtpd[13243]: [ID 197553 mail.info]
disconnect from unknown[134.53.6.74]
The client did not send anything inside 3 minutes. Postfix disconnected.
Whatever is happening, is happening client-side, so you should probably
investigate that.
snoop
1 0.00000 mualmarp02.mcs.muohio.edu -> pmx4 SMTP C port=37488
2 0.00002 pmx4 -> mualmarp02.mcs.muohio.edu SMTP R port=37488
3 0.02686 mualmarp02.mcs.muohio.edu -> pmx4 SMTP C port=37488
4 0.41173 mualmarp02.mcs.muohio.edu -> pmx4 SMTP C port=37500
5 0.00004 pmx4 -> mualmarp02.mcs.muohio.edu SMTP R port=37500
I don't know what "snoop" is, but it appears to screw up the chronology
of traffic.
This should not happen.
# postconf -n
mynetworks = localhost 127.0.0.1 130.68.1.0/24 130.68.4.0/24
130.68.188.0/24 130.68.3.38 130.68.5.24 130.68.20.115 130.68.20.139
130.68.20.25 130.68.20.34 130.68.20.55 130.68.20.67 130.68.20.72
130.68.20.74 130.68.56.15 130.68.56.15 130.68.56.23 130.68.56.23
130.68.56.49 130.68.56.49 130.68.84.201 130.68.84.51 130.68.84.52
130.68.84.53 130.68.84.54 130.68.84.54 130.68.84.56 130.68.84.57
130.68.84.59 130.68.85.93 130.68.120.49 130.68.160.20 130.68.160.66
64.14.35.134 66.111.5.152 69.25.199.3 207.66.21.3 205.237.106.3
69.25.199.33 149.72.3.15
oh. my. god.
--
J.
