Canadian Broadband → How to Access Modem via Tomato Router

How to Connect to Modem through Tomato Router:

This is known to work for Tomato Versions 1.19-1.25 on Linksys WRT54G and WRT54GL Routers.

(For MLPPP versions, skip to the bottom.)

1. Change Router's LAN IP to 192.168.0.1
(your router needs to be on a different subnet from the modem.
Many modems are on 192.168.1.* or 192.168.2.*, so I prefer to pick 192.168.0.1 for the router)

2.you need this only once:
ip addr add 192.168.1.2/24 dev vlan1 brd +
(this will let the router access the modem)

3. you need this at the start, and every time the FW is restarted:
iptables -I POSTROUTING -t nat -o vlan1 -d 192.168.1.0/24 -j MASQUERADE
(this will let every host on the LAN access the modem via the router)

I recommend making this work one step at a time.
#1 from the Web GUI, #2 and #3 from the router's shell, having logged in via ssh or telnet.
After #2 you should be able to see the modem from inside the router. ...

3.1 If this does not work, try the following (shopkins missing magic 10) ip command instead:

ip addr add 192.168.1.10/24 dev vlan1 brd +

Once everything works, put the commands into scripts, to run them automatically:

Init Script:
sleep 5
ip ...
iptables ...

Firewall Script:
iptables ...

. . .

For MLPPP versions:

*. Tomato/MLPPP Version 1.21-mp3alpha4 has a convenient option:
"Route Modem IP" in Basic > Network. (Future versions of Tomato might incorporate this. )

*. For Tomato/MLPPP Version 1.19-mp2 use br1 instead of vlan1 in the above, and note #3.1.

. . .
Readings:
shopkins: »Connecting to modem on Tomato/MLPPP
mactalla: »[HOWTO] Connecting to modem through router
Shada: »Illustrated Easy Single Line MLPPP Setup instructions
heyyahblah: »ST516 Bridge Mode + Router = Access DMT & Modem Config !TUT!
HiVolt: »Any ideas how to Do MLPP ? with xp?

Those are the only two versions that anybody should be using (well, they really should only be using 1.21-mp3alpha4, but 1.19-mp2 is technically the stable release), so what version exactly is your how-to guide intended for?

Thank you very much for this excellent question.

I use Tomato extensively and intensely. I have never used MLPPP.

I can see how someone who is only interested in Tomato as an MLPPP vehicle might be attracted by the Subject line, and then be bored by all the additional "irrelevant" information.

I was trying to make things easy for MLPPP users, but in the process have created an annoyance.

Unless I hear of an even better solution to this conundrum, I will do this:

. . .

1. Change the Subject line to

Modem Access via Tomato Router

2. Move the MLPPP text to the end of the page.

3. Express a hope that the future official releases will do what the latest MLPPP version did.

. . .

Will that satisfy all? Better suggestions?

[FWIY, when people asked how to access modems via Tomato, I showed them how. Then they got annoyed with me because it didn't work for them. Turns out that MLPPP versions did things differently from pure Tomato. So, I took the trouble to learn how these different MLPPP versions differed from pure Tomato, and decided to share everything for the benefit of others.]

=== The changes are done === .

Well, our stuff is all opensourced, so the Tomato author can use any of our code in a future version if he wants to. But I suspect that he won't include anything unless we submit specific patches, which is unlikely.