Using iptables for forward some packets

[Bob Edwards]

Michael Still wrote:
> 
> Hello.
> 
> I am having iptables confusion issues. I have a packet (a DHCP request in
> this case). The packet arrives on my firewall on wlan0, and I want to push
> it straight out eth0. I then need to push the response back the same
> way...
> 
> I have:
> 
> echo "Forwarding selected wireless packets"
> iptables -A FORWARD -i wlan0 -o eth0 -p udp --dport 67 -j ACCEPT
> iptables -A FORWARD -i eth0 -o wlan0 -p udp --dport 67 -s 172.31.0.50/32 -j ACCEPT
> 
> And I'm proud to say it doesn't work. Can I have a hint please?
> 
> Mikal
> 

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.

Cheers,

Bob Edwards.