GENIUSES: IPTABLES to do this....
I own a Linksys WRT54G router with DDWRT firmware. I'm trying to compose a routing policy so that traffic from my local devices connected to the router are either piped through the normal internet traffic or piped through the active PPTP connection.
I am trying to redirect all outgoing www PORT 80 requests through to the PPTP and all other outgoing port requests (eg. 443, 21, etc) through to the normal internet.
From what i can see i need to make use of one or more of the following:
My first attempt i tried using the following:
iptables -t nat -A PREROUTING -p tcp --dport ! 80 -j DNAT -—to-destination 192.168.2.1
where 192.168.2.1 is the IP to the gateway of my router as opposed to the PPTP gateway of 10.x.x.x.
The resulting logs showed this:
Note: vlan1 = internet gateway, ppp0 = PPTP gateway
Making a request from local pc 192.168.1.101 to https : www.google.ca
The problem here appears to be the DST part. The IPTABLES command seems to be modifying the original destination making the outgoing request from my PC useless. I want to retain the proper DST address (eg. 18.104.22.168) but perhaps modify the OUT network interface (from the original ppp0 before the IPTABLES modified it above) to vlan1.
ACCEPT IN=br0 OUT=vlan1
PROTO=TCP SPT=53342 DPT=443
Is there such a command in IPTABLES such as "to-gateway" or "to-interface" that way it modifies the interface to use without modifying the actual request src or destination?
I would advise you to try amending your routing table. I use this to connect to other networks/vlans.