Device MAC Address for a 2911

[Jelani_DTE_PRO]

Which command should I use, to learn the device MAC address for a 2911? I'm configuring Port Forwarding, for access to my lab equipment. And, in haste last night, I executed a "show version" on my 2911s, thinking I would find their respective MAC address within a saved text file. Of course, when I later looked over the files that contain the "show version" info, it's not there. I did find a MAC address of each 2911, after executing a "show arp" on one of my switches. However, that seems to be the interface MAC address...because Port Forwarding, isn't allowing me access to those devices.

And, yes, I was able to access those 2911s with a direct connection to my ISP router...using the protocol I've configured for Port Forwarding.

[ctbower98]

Router#show interface fa0/0

FastEthernet0/0 is administratively down, line protocol is down

  Hardware is CN Gigabit Ethernet, address is 4c00.8262.3c99 (bia 4c00.8262.3c99)

  MTU 1500 bytes, BW 1000000 Kbit/sec, DLY 10 usec,

     reliability 255/255, txload 1/255, rxload 1/255

     .....

[Jelani_DTE_PRO]

Hi. And, thanks for the reply.

However, that looks to be the MAC address for that interface.... I would like to know how to obtain the device MAC Address...

[ctbower98 · Accepted solution]

Each interface will have a MAC address. There is no device MAC address. Whichever interface you are connected to is the MAC address you are sending packets to and from. 

[Jelani_DTE_PRO]

ctb,

I was hoping no one would say that...there's no device MAC address, unlike in the case of a base Ethernet address for a switch. Now, I have to wait 'til this evening to further troubleshoot and get this resolved. UGH! LOL!

Thanks, for your feedback.

[Joseph W. Doherty]

Just to add a note to what ctbower98 noted, if you use a virtual IP, like HSRP, it will have a virtual MAC.

[Jelani_DTE_PRO]

Hi, Joseph.

Isn't that the same (interface) MAC address that can be found, within a "show arp"?

[Joseph W. Doherty]

Yes, it might be seen there.

BTW, if you're looking for a "device MAC", something like a HSRP MAC might suffice as I recall (?) you can use the same HSRP group on different interfaces (i.e. each interface might then have the same virtual MAC.

Also, there might be a command to assign a MAC to a physical interface. If so, you could have different interfaces with the same MAC.