Re: DHCP requests from nodes w/ different subnet masks

[Ray Fleischmann <[e-mail]>]

We are using Novell's DHCP server software. It has an option for adding 
IP addresses from "OTHER" subnetted ranges than the one the server is on. 
We have 5 different subnetted segments of 5 remote sites from the server 
and all is working well.


Ray Fleischmann
Network Specialist IV
(Communications Protocol Specialist)
Broward Community College
225 East Los Olas Blvd.
Fort Lauderdale
Florida   33301
[phone]
[e-mail]

On Mon, 9 Sep 1996, m vossberg wrote:

> I am looking for information on how DHCP handles a request from a client 
> that is on a network that has a different subnet mask than the server.  The 
> scenario would be a PC client on an ethernet network directly attached to a 
> cisco router that uses a class b IP address with a mask of 255.255.255.240. 
> The dhcp server (Sun Ultra running Solaris 2.5.1) is on different network, 
> an ethernet directly connected to another cisco router with the same class 
> b type address with a subnet mask of 255.255.255.192.  The two routers are 
> connected via a demand dial link through the async lines.  The cisco router 
> directly connected to the PC client has an "ip helper-address 
> xxx.xxx.xxx.xxx" of the dhcp server on the other network.  This allows dhcp 
> requests to be directed to the dhcp server.
> 
> As of yet, I have not been able to find any reference to this type of 
> configuration/operation.  We have confirmed that request packets are 
> traversing the routers correctly and getting to the dhcp server.  While 
> running dhcpd in debug mode and using snoop we have seen the client 
> requests, but the server does not respond.
> 
> Does "standard" DHCP provide for such a situation or is this up to the 
> specific vendors to offer this "feature"?  If DHCP does indeed cover this 
> scenario could you please point to the documentation/white papers that 
> describe this operation.
> 
> thanks,
> m vossberg
> 
>