Subject: Re: Patch to change ethernet link addresses
To: Greywolf <>
From: Steven M. Bellovin <>
List: current-users
Date: 08/11/2003 14:16:30
In message <>, Greywolf w
>Thus spake Thor Lancelot Simon ("TLS> ") sometime Yesterday...
>TLS> The correct way to do this sort of thing is with network-layer routing
>TLS> updates, not with disgusting link-layer hackery.
>You might want to tell this to the people who make failover boxes which
>do just this in hardware.  They do exist.  Or, at least, this used to be
>quite a common practice a few years ago.  I never got to manage one, but
>I saw the setup for it.  I believe Cisco's failover HW takes the
>"I-Will-Assume-The-Other's-IP-Address-AND-its-MAC-address" approach.
>Someone will, no doubt, tell me {if,that} I am mistaken.

It's called "Virtual Router Redundancy Protocol", RFC 2338.

		--Steve Bellovin,