3com 4200G MAC learning defect

[zylon]

Hello,

The 3com 4200G has a problem learning specific combinations of MACs.

I was having performanceissues in my network. After searching I learned that my coreswitches (4200G) were not learning specific MACs causing unicast broadcast among other things. I have been able to reproduce it on my testswitches with the following combination:

0030-4800-0ACF, 0030-4800-1ACE 0030-4800-2ACD, 0030-4800-3ACC, 0030-4800-4ACB.

If I attaches two stations to lab4200g-1 and generate traffic from these IP with dynamic MAC learning, only the first 3 will be learned and the 4th will not:

dis mac-address 0030-4800-3acc

Such mac address does not exist!

But on the receiving machine I see:

19:30:26.072978 00:30:48:00:3a:cc > 00:0b:6a:7e:05:a4, ethertype IPv4 (0x0800), length 60: 192.168.1.1.0 > 172.24.254.145.0: Flags [], win 65535, length 0

So the traffic certainly has passed through the 4200G. If the other 3 MACs are not learned, it will learn the 00:30:48:00:3a:cc MAC, so the MACs are conflicting.

If I try to set these MACs statically, only the first 4 will be set and the 5th will give an error:

mac-address static 0030-4800-0ACF interface gigabitethernet 1/0/1 vlan 1

mac-address static 0030-4800-1ACE interface gigabitethernet 1/0/1 vlan 1

mac-address static 0030-4800-2ACD interface gigabitethernet 1/0/1 vlan 1

mac-address static 0030-4800-3ACC interface gigabitethernet 1/0/1 vlan 1

mac-address static 0030-4800-4ACB interface gigabitethernet 1/0/1 vlan 1

Add Mac address failed!

#Apr  1 23:58:40:801 2000 4200G ADBM/5/MAC TABLE ALMOST FULL:- 1 -

MAC table is almost full

mac-address static 0030-4800-5ACA interface gigabitethernet 1/0/1 vlan 1

Add Mac address failed!

Apr  1 23:58:41:032 2000 4200G ADBM/5/MAC TABLE ALMOST FULL:- 1 -

MAC table is almost full

mac-address static 0030-4800-6AC9 interface gigabitethernet 1/0/1 vlan 1

Add Mac address failed!

Apr  1 23:58:41:261 2000 4200G ADBM/5/MAC TABLE ALMOST FULL:- 1 -

 MAC table is almost full

mac-address static 0030-4800-7AC8 interface gigabitethernet 1/0/1 vlan 1

Add Mac address failed!

Apr  1 23:58:41:491 2000 4200G ADBM/5/MAC TABLE ALMOST FULL:- 1 -

MAC table is almost full

dis mac-address

MAC ADDR        VLAN ID   STATE          PORT INDEX               AGING TIME(s)

0013-2028-07be  1         Learned        GigabitEthernet1/0/1     AGING

001c-10f6-c238  1         Learned        GigabitEthernet1/0/1     AGING

0030-4800-0acf  1         Config static  GigabitEthernet1/0/1     NOAGED

0030-4800-1ace  1         Config static  GigabitEthernet1/0/1     NOAGED

0030-4800-2acd  1         Config static  GigabitEthernet1/0/1     NOAGED

0030-4800-3acc  1         Config static  GigabitEthernet1/0/1     NOAGED

0080-77ca-7d0d  1         Learned        GigabitEthernet1/0/1     AGING

0a00-0400-0a04  1         Learned        GigabitEthernet1/0/1     AGING



  ---  8 mac address(es) found  ---

I am running software version v3.02.04s168.

http://knowledge.3com.com/service/main.jsp?t=solutionTab&ft=searchTab&ps=solutionPanels&locale=en_US&_dyncharset=UTF-8&solutionId=1001 has a comment about the ADBM/5/MAC message being harmless, but this is incorrect for this switch. It is harmful because the MACs are not being learned.

Is this a known problem? Is there a solution to this problem?