MAC Addres of A Router LAN iNTERFACE

[jabbar154]

Is there any way to change the MAC address of the Router LAN interface

[Kevin Dorrell]

It looks like the interface command mac-address H.H.H might do what you want. The documentation seems to imply that it is only for TokenRing interfaces; however, my 7506 seems to have the command in its list on an Ethernet interface. (Although I didn't actually try it, for obvious reasons ;-)

If you do try it, be careful about the address you choose. The least significant bit of the first byte should NOT be '1', because this would be a multicast address, ie. 0100.1234.5678 is out. OTOH, it is recommended that the second bit is a '1', which would make it locally administered, e.g. 0200.1234.5678.

Kevin Dorrell

Luxembourg

[Richard Burts]

There is a way to get a router LAN interface to use a MAC address different from the Burned In Address. This is a feature called Locally Administered Address. You use the interface command:mac-address .

HTH

Rick

[amit-singh]

Yes, you can change it.

Got to config t and then the particular interface and then use the command " mac-address xxxx.yyyy.zzzz " and it will change the mac-address of the interface. It will not change the BIA address of that interface.

For ex .

dsl(config)#int fa 0

okhladsl(config-if)#mac-address aaaa.bbbb.bbbb

okhladsl(config-if)#end

okhladsl#sh int fa 0

FastEthernet0 is up, line protocol is up

Hardware is PQUICC_FEC, address is aaaa.bbbb.bbbb (bia 0008.2196.7164)

Internet address is 10.32.11.34/29

MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,

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

okhladsl#sh arp

Protocol Address Age (min) Hardware Addr Type Interface

Internet 10.32.11.34 - aaaa.bbbb.bbbb ARPA FastEthernet0

Internet 151.4.0.151 0 000e.7f61.9388 ARPA Ethernet0

Internet 151.4.0.150 0 0011.250b.adda

HTH,

-amit singh