Re: Source address and source port problem in DHCP server

Ted Lemon wrote:
> On Saturday 02 August 2003 08:06, Jitesh N Verma wrote:
> 
>>Can somebody tell me if checking of the source address
>>of the reply packet with the destination address of the
>>relayed request packet by a DHCP relay agent OK? RFC
>>does not say anything on this issue. I want to know
>>who is not comploying with the RFC? Relay? Or the
>>server?
> 
> 
> If the RFC doesn't say that the relay agent should do this (and it does not) 
> then the relay agent shouldn't do it.   This is a completely wrong to thing 
> do, because it breaks interoperability by imposing a requirement on the 
> server that is not stated in the protocol specification.   I suspect it's a 
> bug in some software version that results from some feature they've added, 
> rather than something they have decided they ought to do in general.
> 
> 

It is an implementation detail - how to match replies to requests. For 
relay, (xid, mac address, message type)-tuple should be sufficient to 
match replies to requests. But in this case, the relay appears to be 
using (server IP address, port sent out on)-tuple to do either matching 
or additional checking. And that's broken.
   For the sake of completion - under some circumstances, matching 
requests to replies using mac address may also not work. And, if the 
relay is attaching option 82 to relayed requests, that could also effect 
the matching logic in relay.

> _______________________________________________
> dhcwg mailing list
> dhcwg <at> ietf.org
> https://www1.ietf.org/mailman/listinfo/dhcwg
>