IPChains and DHCP

[Joel Ryan]

Has anyone using IPChains for IP Forwarding/Masquerading with a network
card that uses DHCP? I am curious because, in all the examples I have
seen, IPChains requires IP addresses for routing. I already have an
IPChains script that creates a firewall, I just need a way to handle
DHCP on one network card.
-- Joel

[shaken]

Joel Ryan <jryan@vsi-hq.com> wrote:
>Has anyone using IPChains for IP Forwarding/Masquerading with a network
>card that uses DHCP? I am curious because, in all the examples I have
>seen, IPChains requires IP addresses for routing. I already have an
>IPChains script that creates a firewall, I just need a way to handle
>DHCP on one network card.
>-- Joel
>
Joel,
All you have to do is add:
#******************************************************
# DHCP STUFF
#******************************************************
#
/sbin/ipchains -A input -j ACCEPT -i eth0 -s 0/0 67 -d 0/0 68 -p udp
echo 1 > /proc/sys/net/ipv4/ip_forward
#
#Timeouts needed for DHCP requests
#1 hr timeout fot TCP timeouts
#10 sec timeout for traffic after the TCP/IP "FIN" packet is received
#160 sec timeout for UDP traffic (Important for MASQ'ed ICQ users)
/sbin/ipchains/-M -S 3600 10 160
#
#Be sure to edit /etc/sysconfig/network from:
#FORWARD_IPV4=false
#to
#FORWARD_IPV4=true


This should do it.

shaken