Or better yet switch to a new mail server???
Kevin Bilbee > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] Behalf Of Markus Gufler > Sent: Tuesday, March 01, 2005 9:10 AM > To: [email protected] > Subject: [IMail Forum] To anyone who bought a 3Com Nic > > > Note: maybe this is not new for certain people on this list but as it was > not easy for me to resolve it, and also neither Ipswitch seems to > know this. > So I want to tell you what happened me with our brand new server: > > Our new Win2k3 Dell server with Dual Xeon CPU's, 2 Intel and 2 Broadcom > Nic's has had the problems that after a short time of higher smtp traffic > more and more connections failed. This problem was already described by > several people on this list, and Ipswitch's solution was to buy "a bether > NIC" (I must laugh again any time I hear it :-) > > Well, the problem was here, the new machine seemed working poorer then our > previous "4 year old noname-assembled server" with realtek NICs. > > It was a little bit of work to explain to other people in my > company that we > need a "bether NIC", nobody has heard this before even if working for over > 15 years in the hardware/server business. Ok new 3Com neek > arrived, disabled > 4 (four!) preconfigured Dell NICs and attached the 3Com card to > the network. > > Run the test again: gatewaying 1000 messages each one send with a delay of > 300 ms trough the server. (more the 260000 msgs/day) > Surprise! The previously in hundreds appearing "MX CONNECT FAILED" and > "status=3"-lines in the logfiles has reduced down to around 30. > > But successfull delivering 970 fom 1000 messages it not > acceptable, even if > the missing 30 was requeued and delivered with the next queue run! > > Searching the archives I've found Sanford Whiteman's post about > TCP registry > settings: > http://www.mail-archive.com/[email protected]/msg94971.html > > After changing this two values (TcpTimedWaitDelay: 60 seconds / > MaxUserPort > = 25000 ports) there was not more one single "MX connect failed" or > "status=3" in the logfiles. All messages was delivered immediately. > > Watching the "forgotten" TCP-connections left by Imail in WAIT-STATE with > "netstat -n 5" I've discovered that the connections from the random local > port to the remote port 25 remain in wait state for a to long time > (default=240 seconds) so that after reaching the default > MaxUserPorts limit > of 5000 and beginning new from port 1 on each try to connect from an local > port already in WAIT-STATE will cause a MX CONNECT FAIL and so a > requeueing > of this message. > > So by reducing the TCPTimedWaitDelay down to 60 and increasing the > MaxUserPort there was enough time for the OS to free up the forgotten > WAIT-STATE connections before the connection limit was reached > and so there > is no more conflict and no more errors. (until the number of processed > messages in a short timerange will become high enough to catch the tail > again) > > Now back to the subject of my post: Removed the 3Com re-enabled the Intel > Nic with the new registry settings suggested by Sanford: No errors even if > sending 400000 messages trough the server. It seems to me that the onboard > NIC of the DELL processor are even more performant then the 3Com nic but > that is not confirmed by a scientific test. > > So please forward the bills of your 3Com NICs to Ipswitch, or maybe ask a > credit to buy ICS... ;-) > > Markus > > > To Unsubscribe: http://www.ipswitch.com/support/mailing-lists.html > List Archive: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/ > Knowledge Base/FAQ: http://www.ipswitch.com/support/IMail/ > To Unsubscribe: http://www.ipswitch.com/support/mailing-lists.html List Archive: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/ Knowledge Base/FAQ: http://www.ipswitch.com/support/IMail/
