[plug] DHCP vs firewall

[Sol]

I'm having a nasty conflict between DHCP client and a firewall which I
have spent hours trying to fix without success. I'm running Debian Woody
as a gateway server to an ADSL (D-link DSL 300) modem that is running
pppoe. (I can't run pppoe on the box ATM.) With the firewall off ADSL
works fine. When it's on the modem connects to the internet and assigns
an IP to the box, but that's as far as things get. The logs are full of
complaints like this from daemon.log:

Dec  1 13:20:15 localhost dhclient-2.2.x: send_packet: Operation not
permitted
Dec  1 13:20:33 localhost dhclient-2.2.x: DHCPDISCOVER on eth0 to
255.255.255.255 port 67 interval 3
Dec  1 13:20:33 localhost dhclient-2.2.x: receive_packet failed on eth0:
Network is down
Dec  1 13:20:33 localhost dhclient-2.2.x: DHCPOFFER from xxx.xx.xxx.184
Dec  1 13:20:36 localhost dhclient-2.2.x: DHCPREQUEST on eth0 to
255.255.255.255 port 67
Dec  1 13:20:36 localhost dhclient-2.2.x: DHCPACK from xxx.xx.xxx.184
Dec  1 13:20:36 localhost dhclient-2.2.x: bound to xxx.xx.xxx.183 --
renewal in 30 seconds.

In the firewall there is an entry pertaining to DHCP, but to the server,
not the client:
# DHCPd -
$IPTABLES -A INPUT -i $INTIF -p tcp --sport 68 --dport 67 -j ACCEPT
$IPTABLES -A INPUT -i $INTIF -p udp --sport 68 --dport 67 -j ACCEPT

I can't find anything else relevant to dhcp in the firewall file, but
then I'm a dodo when it comes to firewalls. I've tried reading about it
but I still haven't a clue how to allow traffic from my ADSL modem through.

All help appreciated,

sol