Tomato/DD-WRT router to act as switch & only NAT some port
- by fseto
BACKGROUND: I have a device that must use a real IP address. Currently, my ISP uses DHCP and I can have up to 4 real IP address assigned. However, the cable modem only have 1 ethernet port and it's connected to my router (running Tomato, but can run DD-wrt or other Openwrt if required). Question stems from how I can connect the additional device, requiring a real IP?
EASY SOLUTION: would be to get a switch and connect to the CM, Router, and Device. But alas, I want to avoid this route, since:
my wiring cabinet in my home is drawing lots of power and heat already
Device will be unprotected by any firewall
unable to monitor the traffic to/from device.
Besides, what would be the FUN in that? =)
IDEA: So what I want to do is to configure the router, so that one of the switchport is removed from the normal br0 bridge. Instead, I want to make it behave like a switch on the WAN port.
What's the best way of doing this? Should I create another bridge on the WAN & the device port? Can a single port belongs to two bridges? or would I need to create a subinterface first? Would I need a DHCP-relay? Am I expecting too much from my poor cheapie router?
+------+
| CM |
+--++--+
||
+----WAN---------------+
| / \ Router |
| BR1? BR0 |
| | \ |
| | {NAT} |
| | / | | \ |
+-P0----P1-P2-P3-Wifi--+
|
+------+
|Device|
+------+
