[K12OSN] dhcp leaking out eth1

[Les Mikesell]

On Mon, 2005-09-12 at 13:51, William Fragakis wrote:
> Don't know how this is happening - apparently some of our newly 
> installed servers (k12ltsp 4.4.0)
> are serving dhcp off eth1. Physically, it's the only connecting to the 
> school network which has its own dhcp server on a 10.x.x.x subnet. eth0 
> is happily handing addresses out on 192.etc and clients are working 
> fine. /var/lib/dhcpd/dhcpd.leases (i hope I didn't misspell anything 
> material) indicates ip addresses handed out to Windows machines on the 
> school network.
> 
> Some we having fully connected and are handing out ip addresses over 
> eth1, a couple are new installs without clients which are doing it.
>
> These are supposed to be default installs with eth0 being local and 
> eth1 being internet. The network config panel reads correctly. Cables 
> are correct, too - or at least we double checked 10 times and it seemed 
> okay.
> 
> We've done a number of identical Dell boxes as servers and only a 
> couple are acting up.
> 
> Is there anything I'm missing? Any way to force dhcp serving to only 
> one ethernet port?

Dhcpd should require a subnet declaration with addresses that match
those assigned to an interface to serve anything - and at startup
you should see an error message about that declaration being missing
for your eth1 interface.

Most likely explanation is that you somewhere have a physical connection
between your inside and outside switches.

-- 
   Les Mikesell
    les at futuresource.com