shared-network question

Bruce Hudson Bruce.Hudson at Dal.Ca
Mon Oct 23 16:43:58 UTC 2006


>>     You need some other mechanism to decide which requests each server
>> should handle.
> 
> Maybe I misunderstand the shared-network, but its my understanding that
> with a shared-network, the DHCP server will hand out an IP from ANY
> subnet in the shared-network, so if the giaddr is from 1 of the subnets
> in the shared-network, shouldn't the server assign an address from
> either of the subnets? If so, couldn't I just not include a range
> statement for the subnet I don't want to assign addresses from?

    You understand how a shared-network works, at least as well as I do.
However, take a step back and look at the entire process. A client turns
on and broadcasts a DHCP DISCOVER on the network, a UDP packet from
0.0.0.0/68 and to 255.255.255.255/67. The router/relay agent fowards this
to both DHCP servers and both servers offer an address from what-ever pool
matches the request. The client then picks one of the offers and proceeds
with a REQESTED for that address. Normally this will be t

    Something, somewhere has to know how to distinguish which service a
client should be configured to use. This can be done by the client, by the
servers or by the relay but something has to if the result is not going to
be more or less random.

> FYI, Cisco has a feature called 'ip dhcp smart-relay'.

    I don't think that will help in your case.
--
Bruce A. Hudson				| Bruce.Hudson at Dal.CA
UCIS, Networks and Systems		|
Dalhousie University			|
Halifax, Nova Scotia, Canada		| (902) 494-3405


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