Using iptables for forward some packets

[Michael Still]

On Tue, 2 Jul 2002, Bob Edwards wrote:

> You might want to run dhcrelay (man dhcrelay(8)) on your router as I
> don't think that your router is likely to want to forward the DHCP
> request packets (which are broadcasts) onto the other subnet.

Hmmmm. I have dhcrelay, and I tried running it with -i wlan0 172.31.0.60,
where wlan0 is my wireless interface and 172.31.0.60 is the DHCP server on
the network, but it brings me no joy. Even with *.* in /etc/syslog.conf
pointing at /var/log/messages it doesn't give me any debugging output
either.

Are there any obvious gotchas which I should know about? iptables -L gives
me:

Chain INPUT (policy ACCEPT)
target     prot opt source               destination
ACCEPT     tcp  --  anywhere             anywhere           tcp dpt:telnet
logdrop    all  --  anywhere             anywhere           state INVALID,NEW

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination
logdrop    all  --  anywhere             anywhere           state INVALID,NEW

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination

Chain logdrop (2 references)
target     prot opt source               destination
LOG        all  --  anywhere             anywhere           LOG level warning
DROP       all  --  anywhere             anywhere

But I can't see anything wrong with this.

Mikal

PS: If I ifconfig the wireless interface on my laptop, then I can ping the
firewall...

-- 

Michael Still (mikal at stillhq.com)     UMT+10hrs