I am having a problem with an ethernet switch that is locking up, trying to find the root cause.
The switch is a 16 port, 10/100Mbps, Linksys model EZXS16W. I have three computers connected to it: Computer "A" is a Windows XP Pro machine running a FTPD server (Guild FTPD). Computers "B" and "C" are CPU boards in an avionics box, both running VxWorks.
When the avionics box powers up, computers "B" and "C" attempt to communicate with computer "A", both using port 5000. After a few seconds computer "A" reports an error that it is unable to communicate with computer "B".
At this point I tried to ping computers "B" and "C" using computer "A" (ping fails), And tried pinging all three using a fourth computer connected to the switch (also fails). I concluded the switch is locked up. Power cycling the switch restores operation until it locks up again.
I tried two other identical EZSX16W switches (same revision, same firmware) with multiple avionics boxes: Two of the three switches always lock up when used with the first avionics box. None of the switches lock up when used with other avionics boxes. Two D-Link switches do not lock up when used with any avionics box. None of the switches lock up since I updated software in the first avionics box. All of the above results are the same if I use another computer "A".
OK, so I solved the problem (updated software in the avionics box), so apparently the ethernet switch doesn't like some traffic going through it. But I have a customer who wants to know why.
Any ideas what caused two of three switches to lock up?