DHCP failover setup with several relay agents

[Robert Blayzor]

On Sep 22, 2008, at 10:17 AM, Chuck Anderson wrote:
> Why do you want to do this?  DHCP is designed to handle the case where
> requests are relayed to multiple servers simultaneously.  You can
> either create multiple Cisco ip helper statements, or use a directed
> subnet broadcast address of both/all servers are on the same subnet.



I can think of a few of reasons actually, but the most important is  
that DHCP is UDP, which means just because you're sending to two  
servers doesn't guarantee that both servers will see those packets, so  
it'd be very easy for there to be lease/database inconsistency.  The  
same thing could happen over a LAN I assume, but that would be very  
rare... when you're talking about relay agents over several WAN hops  
away... that's a different story.

-- 
Robert Blayzor, BOFH
INOC, LLC
rblayzor at inoc.net
http://www.inoc.net/~rblayzor/