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3com 4200G MAC learning defect

 
zylon
Occasional Visitor

3com 4200G MAC learning defect

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?