Odd MAC addresses -DHCP on Cisco 2911and 1941

[jprudencio7591]

Hello,

I seem to be getting odd MAC addresses showing when I run "sh ip dhcp bind" on any of 3 Cisco routers with DHCP enabled that I have.

(see pic)

Am I missing something here? Is 013c.15c2.2b1f.23 a valid MAC address?

[lpassmore · Accepted solution]

Hello back

The 01 component of this is a media type (01 means that it is Ethernet - I haven't seen any other values).  Some operating systems (e.g. Windows) send this along with the MAC address 3c15.c22b.1f23 as the client identifier.

You can also set the option in a Cisco device that uses DHCP for obtaining and address.  An example can be found here - search for media type

http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/ipaddr_dhcp/configuration/15-mt/dhcp-15-mt-book/config-dhcp-server.html