Ben, from your diescription it sounds to me like a flaky ethernet controller or associated board magnetics.
Many years ago, I had one workstation NIC that turned out was periodically losing its mind and spewing gibberish for several minutes then suddenly work normal again. As you can imagine, this caused all kinds of mysterious network problems. Fortunately, it was connected to a 3COM 24-port managed switch, and the mystery was cleared up when I happened to notice the hundreds of thousands of errors on one particular switch port in a SNMP report! 1. REPLACE the server's ethernet cable (even if it looks good). 2. Run the INTEL diagnostics/utilities for the server board. 3. Check Windows Event log (System AND Application) for anything slightest bit suspicious that could be a precursor event. 4. If you have a managed switch that you can connect directly to the server, use it as a reporting tool. If NoJoy, you may want to consider a 15 minute diagnostic shortcut: Simply disable the onboard NICs in the BIOS, and temporarily toss in a couple Intel or 3COM PCI NIC's. If the crash problems cease, you know that the onboard ethernet controller or magnetics was the culprit. If the issue continues, you definitely need to sniff the wire hoping to catch the storm trigger sequence. Good Luck! Dev -----Original message----- From: "IMail Admin" [EMAIL PROTECTED] Date: Sat, 16 Apr 2005 00:00:48 -0700 To: [email protected] Subject: Re: [IMail Forum] diagnosing server crash > My apologies; I sent my reply to the wrong message. It's been a long day... > > Here is what I meant to send in response to Dev's message: > > The motherboard is an Intel SCB2, which has integrate NICs. These are very > reliable server boards. We have several such machines, all running the same > drivers and setup, without problems. The thing is, it seems like the LAN > with that server (and the few others) is getting overwhelmed, possibly with > a broadcast storm. Once the crash occurs, the server is frozen and the > other servers cannot use the LAN (e.g., to reach the router and the > Internet). > > Ben > > ************************************** > Actually, we've gone down twice more, and it's still pretty mysterious. The > NICs show no signs of problems; in fact, the server seems perfect. But it > freezes up, and the network is overloaded so that nothing else can use > network. I can unplug the mail server, and then the network is usable > again, which proves that there is some sort of broadcast storm in connection > with the mail server. However, the server itself is frozen, and must be > rebooted. I'm at a loss. > > Ben > > ----- Original Message ----- > From: "Dev" <[EMAIL PROTECTED]> > To: "Imail Admin" <[email protected]> > Sent: Friday, April 15, 2005 5:23 PM > Subject: Re: [IMail Forum] diagnosing server crash > > > > Check your NIC and NIC driver. > > > > > > Friday, April 15, 2005, 4:45:40 PM, you wrote: > > > > IA> We have an IMail server (v. 7.15) that crashed twice today. The same > > IA> problem occured once, several weeks ago. The > > IA> crash is a little strange: > > > > IA> 1. The even log shows no error messages, > > IA> except that there was a dirty > > IA> shut-down. > > IA> 2. The system shows no other problems, hardware or software. > > IA> 3. That server is on a switch with a couple of > > IA> other public servers. When > > IA> the crash occurs, it kills all traffic through > > IA> that switch. Nothing gets in > > IA> or out. Reboot the mail server, and the problem goes away. > > > > IA> Normally, with a crash I would look at > > IA> software first. Then, if nothing has > > IA> changed in the software, I would look at the > > IA> hardware. In thise case, > > IA> everything looks clean. So what else could it > > IA> be? I wondered if this could > > IA> be a DOS attack that overloaded the server and > > IA> tied up the network? What do > > IA> you think? > > > > IA> Ben > > IA> BC Web > > > > > > > > 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/ 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/
