Router MAC Addresses

[Carlos Aguinaldo]

Hello all.

Is it correct that routers don't have a base Ethernet MAC address (but switches have) and the only MACs that routers have are the BIAs in the interfaces?

[Carlos Aguinaldo]

Keeping this thread alive.

Thanks

[Collin Clark]

Depends. Are you talking for something like spanning tree or for something like HSRP/VRRP? Generally speaking in STP, a switch has a base MAC (chassis's use the Sup MAC, stackables typically use use lowest interface -1).

[Carlos Aguinaldo]

Hello Collin.

Depends. Are you talking for something like spanning tree or for something like HSRP/VRRP? Generally speaking in STP, a switch has a base MAC (chassis's use the Sup MAC, stackables typically use use lowest interface -1).

Is the base MAC used for STP different from the one used in HSRP? I'm actually referring to the base MAC shown in the output of sh version on a switch. I just noticed that routers don't have a base MAC in the output of sh version.

[Collin Clark · Accepted solution]

Yes the MAC's are different. Routers don't have a system MAC (they may with the ethernet HWIC card installed though).

[Carlos Aguinaldo]

Thanks for clarifying this. So you won't see a base Ethernet MAC on a router unless you have an Ethernet HWIC card installed. Alright. Though I don't have an HWIC card to test this, can you please mention what command should be used to view the base Ethernet MAC incase an Ethernet HWIC card is installed on a router?