dhcrelay over wireless mesh

[Luca Tavanti]

Yes, I'll definitely give the sniffer a try...

On 11/07/12 17:13, Simon Hobson wrote:
> Luca Tavanti wrote:
>
>> Now, my setup is as follwos:
>>
>> ((( 0 ))) ((( 1 ))) ((( 2 ))) ((( 3 )))
>>
>> I put the dhcp server on node 0, and both a dhclient and a dhcrelay on
>> nodes 1,2,and 3.
>> In this way both nodes 1 and 2 gets an IP from the server (directly
>> for node 1, through the relay on node 1 for node 2).
>> Yet, node 3 never gets an IP.
>
> Use <your preferred packet sniffer> at the various network points to see
> what's being transmitted. In particular, see if a packet from node 3 is
> reaching node 0 at all, and if so, what it's GI Addr field contains.
> Also, look at how nodes 1 and 2 are getting their addresses.
>
> My guesses at what's going wrong ...
>
> The relay agent on node 1 is changing the GI Addr value in the packet,
> hence the reply doesn't go back to node 2 and so doesn't get broadcast
> back to the client.
>
> The server is getting confused by the GI Addr being on a locally
> connected network, is broadcasting the reply, and the relay agent on
> node 1 is relaying it to node 2 (for node 2 getting it's address).
>