4400 WLC - Same MAC on different interfaces ????????

armonk_netdesk · ‎05-14-2008

This can't be right. Why is it that a 4400 controller advertises the same MAC address on multiple interfaces. It is confusing the hell out of the layer-3 switch it is trunked to. Here is the ARP table from the switch.... As you can see MAC 0018.ba49.af47 shows up on VLAN 352 and 353. What gives ????

Protocol Address Age (min) Hardware Addr Type Interface

Internet 69.74.38.49 - 0014.6abc.3ac1 ARPA Vlan351

Internet 69.74.38.48 0 00d0.8304.f90e ARPA Vlan351

Internet 172.20.200.1 - 0014.6abc.3ac4 ARPA Vlan360

Internet 192.168.200.1 - 0014.6abc.3ac3 ARPA Vlan353

Internet 192.168.200.2 100 0018.ba49.af47 ARPA Vlan353

Internet 172.20.192.140 68 0018.ba49.af47 ARPA Vlan352

Internet 172.20.192.141 69 0018.ba49.af40 ARPA Vlan352

Internet 172.20.192.129 - 0014.6abc.3ac2 ARPA Vlan352

Internet 172.20.192.130 236 0018.ba49.afa7 ARPA Vlan352

jeromehenry_2 · ‎05-15-2008

If 1 of your controller port has dynamic interfaces, they will be seen as the same MAC address on the switch... not really an issue on our system... what problem does it create on yours?

armonk_netdesk · ‎05-19-2008

I turned on ARP debugging on the layer3 switch that the 4402 is attached to via LAG.

I get these errors in the log....

----------------------------------------------

May 19 20:18:56 UTC: IP ARP req filtered src 192.168.200.2 0018.ba49.afa4, dst 192.168.200.1 0000.0000.0000 wrong cable,

interface Vlan352

May 19 20:18:57 UTC: IP ARP req filtered src 192.168.200.2 0018.ba49.afa4, dst 192.168.200.1 0000.0000.0000 wrong cable,

interface Vlan352

-----------------------------------------

The 192.168.200.x addresses belong to VLAN 353. The management interface is on VLAN 352. So why is the management interface sending ARP requests for dynamic interfaces?