Cable Internet and DSL (or AT&T u-verse) at the same time, how to access files or use SVN across two different networks?

Question

I had DSL and then signed up for Comcast Cable internet coz it is said that it is really fast (even though can be unreliable sometimes). And then I upgraded from DSL to AT&T U-verse's fiber optics with 6Mbps down and 1Mbps up.

So now some of my PCs are on the Comcast network hooked up to the Linksys wireless router, and some PCs / notebook / Mac are connected to the AT&T U-verse fiber optics that has a wireless router provided with the service.

So it became very hard to access files between these two networks. If I want to read a file that happens to be on another network, I may need to connect to a different wireless... or unplug the cable from one router to another...

the same is true if i want to SVN commit some files. If the PC is not on that network, then I either need to find out the SVN's PC's IP address, or connect to a different network.

So is there a way to make it easier? There is a PC that has both a LAN card and a wireless card. So that computer might be able to connect to both networks and pass data around?

Answer 1

I will first suppose that both of your networks are physically close to each other and that you can easily pull a cable from one to another. This will enable you to pull a little routing trick if your router is good enough (can't know, not enough details)

Have the two networks in two distinct subnets, let's say 192.168.1.0/24 and 192.168.2.0/24 with the routers at .1. Pull a cable in between your routers and create a little subnet for that, let's say 192.168.254.0/30. Then all you have to do is to add static routes to point one router to the other :-)

Another simpler option is to have a big network with a big subnet let's say 192.168.0/22. So yes, this means putting all of your PCs in the same LAN. Then all you have to do is point the PCs you want to use FO to the FO gateway and point the PCs you want to use Cable to the cable gateway. Disable one of the DHCPs (or all) because this will create strange conflicts.

Another option is to put an IPsec gateway between the two routers but that means having your interco traffic passing via the internet which is not so good of an idea.