From: Bob Sinclair (bob@bobsinclair.net)
Date: Mon Nov 19 2007 - 15:32:22 ART
Group:
When asked to discover the subnet on an attached FastEthernet Interface
I usually guess an IP and turn on debug ip packet, hoping to see some
broadcast traffic, or traffic for an enabled protocol.
Lately I have seen the following technique, and could use your input:
Guess an IP address, turn on debug arp, and ping 255.255.255.255. In a
context using 2811s running 12.4 code, I saw an ARP "wrong wire"
message with the source address of another router on the subnet.
This would be cool in a lab situation because it would seem not to rely
on any special configuration on either router.
But I cannot get this to work on a 3640 with 12.4 code and no longer
have access to the 2811s. Any ideas what is going on? Have you seen
this arp "wrong wire" message sent? Is it IOS or platform specific? I
checked Google and likely arp commands in the Doc CD, but didn't see
anything helpful.
Thanks!
--Bob Sinclair CCIE 10427 CCSI 30427 www.netmasterclass.net
This archive was generated by hypermail 2.1.4 : Sat Dec 01 2007 - 06:37:30 ART