3COM Baseline Switch 2924-SFP Plus Port shut down

[Mick_1]

3COM Baseline Switch 2924-SFP Plus Port shut down occassionally!!!

I have 3COM Baseline Switch 2924-SFP Plus. Its ports connects to unmanaged switches. For port #3 I create MAC based ACL, here it is:

mac access-list "612 port3"

permit 00:17:31:4d:f1:52 00:00:00:00:00:00 any

permit 00:14:85:e1:af:53 00:00:00:00:00:00 any

...........................................................................................

...........................................................................................

permit any 00:19:d1:61:6d:49 00:00:00:00:00:00

permit any 00:c0:26:28:88:c9 00:00:00:00:00:00

deny disable-port any any

exit

(some ACE omitted to shorten)

This ACL is binding to port #3:

interface ethernet 3

service-acl input "612 port3"

exit



To this port connected 24 ports unmanaged switch with about ten computers connected to its ports.

Further, it's a part of system log:

28-May-2009 09:32:21 Info %LINK-I-Up: 3

28-May-2009 09:31:05 Warning %STP-W-PORTSTATUS: 13: STP status Forwarding

28-May-2009 09:30:35 Info %LINK-I-Up: 13

28-May-2009 09:30:30 Warning %LINK-W-Down: 13

28-May-2009 09:20:22 Info %AAA-I-CONNECT: New http connection for user admin, source 169.254.0.33 destination 169.254.1.10 ACCEPTED

27-May-2009 20:03:08 Warning %LINK-W-Down: 3

27-May-2009 19:39:50 Warning %STP-W-PORTSTATUS: 3: STP status Forwarding

27-May-2009 19:39:50 Warning %STP-W-PORTSTATUS: 4: STP status Forwarding

27-May-2009 19:39:20 Info %LINK-I-Up: 3

27-May-2009 19:39:20 Info %LINK-I-Up: 4

27-May-2009 19:39:19 Warning %LINK-W-Down: 4

27-May-2009 19:39:19 Warning %LINK-W-Down: 3

27-May-2009 18:11:25 Warning %STP-W-PORTSTATUS: 3: STP status Forwarding

27-May-2009 18:10:55 Info %LINK-I-Up: 3

27-May-2009 18:10:53 Warning %LINK-W-Down: 3

We see link down then up then down again an finally, till I activate port #3 over Web Interface.

The users say they don't connect other device to unmanaged switch. If so,

why this port down?



Any assistance will be greatly appreciated.



Kind Regards,

Mick