dhcrelay does not relay answers back to client

Peter Daum gator_ml at yahoo.de
Sat Mar 12 08:34:40 UTC 2011

On 2011-03-12 01:20, Glenn Satchell wrote:

> Note that the correct usage is to listen on interface where client
> requests will be coming from *and* the inteface where replies from the
> server will also come from. Usually this means you want to listen on al
> lthe interfaces (the default behaviour).

I read this in the manpage, but since dhcrelay didn't seem to use the
VPN tunnel device and all the answers coming back from the dhcp server
are unicast to the address set on the ethernet interface that dhcrelay
is listening on I had hoped it might somehow work anyway ...

> A simple workaround is to run the dhcrelay on a different system on the
> lan behind gateway2. Here it can listen on eth0 and all should work as
> expected.

The only connection between the site with the DHCP server and the site
where the clients and the dhcrelay are is via the VPN and the host that
I am trying to run dhcrelay on is the only machine that is permanently
running there (It is just a small branch office with a DSL line). As far
as I can see, my only hope would be to relay over the VPN tunnel.
(Unfortunately my possibilities are generally limited because "Gateway2"
is just running a "Devil Linux" life system)


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