DD-WRT Network Sniffing

My DD-WRT router unfortunately does not have the option to create a TAP/Mirror Port, but using IPTables we can make a copy of all traffic and forward it to a IP:

SSH to your Router, in this case we are going to forward traffic to my IDS on: 192.168.1.200

iptables -A PREROUTING -t mangle -j ROUTE --gw 192.168.1.200 --tee
iptables -A POSTROUTING -t mangle -j ROUTE --gw 192.168.1.200 --tee

To confirm the rules have been created we can run the following command:

iptables -L -t mangle

To remove the rule we run the following command:

iptables -F -t mangle