DHCP Relay + PPP (your mail)

Glenn Satchell Glenn.Satchell at uniq.com.au
Wed May 24 11:51:44 UTC 2006

>Date: Tue, 23 May 2006 23:34:46 +0100
>To: dhcp-users at isc.org
>From: Simon Hobson <dhcp at thehobsons.co.uk>
>Subject: Re: DHCP Relay + PPP (your mail)
>Thinking more about this, things are even simpler that I first 
>thought - unless you know differently that is !
>The relay agent has only one function, to receive broadcast packets 
>from clients which are forwarded to the dhcp server, and to broadcast 
>the returned packets. To deal with the broadcast packets requires 
>jumping through the hoops it does.
>However, handling the packets from the dhcp server is surely a 
>trivial exercise - all that is required is to open the right port (67 
>or 68 ?) on any IP address(es) that the relay agent might use for the 
>GIAddr. The actual interface doesn't matter and probably isn't the 
>real interface that the packet arrives on from the server - you just 
>need to be able to receive a unicast packet to the GIAddr.
>If done that way, then there would be no need to worry about the 
>technology of any upstream connections - only that of the client 
>networks. Also, the only configuration required would be the 
>network(s) to listen on for client broadcasts (and server 
>address(es)) - certainly no need to worry about how server reply 
>packets will arrive.
>Have I missed something blindingly obvious ?
What about the situation where the relay is running on a system with
only a single interface? It needs to be able to listen and transmit on
the one interface.

PS to Joby, this type of network configuration should also work for
you, and you only need one interfce in the relay box, rather than using
it as a router.


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