Strange DHCPINFORM

[fadey]

Thanks a lot for your reply, David

Yes, I'm running quite old dhcpd version (3.0.1). This is the version
that CentOS 4.6 has in its repo.

I'm using the dhcp in a cable network (docsis). All DHCP requests from
clients are being relayed to the dhcp server by the main router's (CMTS)
relay agent. 

clients_network->CMTS_router->dhcp_server

So, my doubt is, who is responsible for that 0.0.0.0 source address in
the INFORM packet? Is it the client's machine or router's relay agent

We had an incident last Friday in our network.
After this line in the log (I've just changed the real IP to 1.1.1.1) we
stopped receiving dhcp traffic until we have restarted the router 2
hours later:

May 15 21:19:51 mydhcpserv dhcpd: DHCPINFORM from 1.1.1.1 via eth1:
unknown subnet 0.0.0.0

If anyone has experienced something like this before or knows of how I
could obtain more information to resolve it, if it happens againg,
please answer.

Thanks in advance.


> On Fri, May 16, 2008 at 02:10:43PM +0200, fadey wrote:
> > May 15 21:19:51 mydhcpserv dhcpd: DHCPINFORM from 1.1.1.1 via eth1:
> > unknown subnet 0.0.0.0
> > 
> > Please, could anyone tell me what does that "unknown subnet 0.0.0.0"
> > mean?
> 
> For one thing, it means you're running old software, as we have
> changed that log line.
> 
> 1.1.1.1 is either the ciaddr field set by the client, or the packet's
> IP source address.  0.0.0.0 is the giaddr field (in this case
> indicating the client was not relayed).
> 
> I think this is a condition the author of the software thought to be
> unlikely or broken.
>