Bridging networks

[lucas.robb]

Hello All,

I've always had a dream of having a tech-savvy neighbour who would want to venture this with me, but I wanted to know what it would take to make it happen. I would like this setup, having house A with an internet connection, router and various networkable resources (we'll say subnet 192.168.2.0/24) and house B also with an internet connection, router and various networkable resources (we'll say subnet 192.168.1.0/24). I recently was working with a setup of bridging two routers and using IP tables to forward all requests to the devices through the routers, but in this setup there is only one internet connection. Using a firmware such as DD-WRT, what would it take to set this up?

Thank you,

 

[abailey]

If you are just looking to hook the networks together so each house could see resources at the other house, then Just a router at each house with DD-WRT would work. Personally I would make a third subnet, like 192.168.10.0/24 for the link between the two houses. Now if you were also trying to do a failover type thing so if the internet failed at one house, that house would route its traffic out the internet connection at the other house, then that gets more complicated.

 

[azazel1024]

So you want to be able to access resources on from and to both networks? If that is the case, you are probably better off bridging the networks and keeping it one IP range for simplicities sake.

Just set them all to 192.168.1.x and have a DHCP server on one side or the other of the network. Then setup, ideally, a pair of routers in WDS bridge mode to wirelessly connect the networks. Probably best off, unless physically very close, to slap on directional antennas on the routers pointed at each other and set them on a channel neither network is using, like say 2.4GHz channel 1. Then have a seperate router/AP providing actual wifi coverage to each house and a router at the internet head in in whichever house is actually providing the internet connection.

If you want physically seperate networks, then you have the two routers in bridge mode and then you have a seperate router connected to each bridge (though maybe DD-WRT can do WDS and use the wireless bridge as a WAN connection, dunno) with the WAN port connected to the bridge and port forward the IP range to each network. Or really just one router on one side connected to the bridges with the WAN port going to one of the physical networks.

Though maybe DD-WRT allows more than a block /24 range so you can have both ranges accessible without any port forwarding (IE provide DHCP and routing for both a 192.168.1.x and 192.168.2.x).

 

[abailey]

So you want to be able to access resources on from and to both networks? If that is the case, you are probably better off bridging the networks and keeping it one IP range for simplicities sake.

This would be simpler but if you want to be able to use both internet connections you would have to either give one of the houses all static addresses so you can specify its default gateway, or possibly create two DHCP ranges on the same subnet and have them tied to MAC address so they give the correct default gateway to each house.
If you did not want to do this then you need to route between the two networks.

 

[azazel1024]

True, but it sounded like the OP was looking at one internet connection shared between the two households. I assume either as an interest project or a cost saving project.

In any of those situations though, there is no failover, other than manual. If you really want "shared" internet connections you'll need a load balance router or one with failover setup and then have both networks use that one router as the gateway.

 

[lucas.robb]

Hello All,

so this is simply an interest project. I am able to use IP tables for forwwarding and static routes to be able to have networks connect to eachother with one internet connection, I was asking more for the purposes of resource sharing. It seems as if what most of you are saying is that if the two networks lived on the same subnet 192.168.1.0/24 (suppose DHCP started at an IP range of 50-100, and the other at 100-150 to avoid IP conflicts) then they would see eachother, but what I'm wondering, suppose I wanted to watch movies and TV shows between the houses, this might be more strenuous then the wireless could handle, so I wanted to be connected via a cat5 cable between the two. I've looked into failover setup which is actually doable with DD-WRT (I found the how to online) but nothing in the regard to having two separate routers with two separate internet connections.

Would love to hear more feedback, thank you for all of your suggestions so far!

 

[azazel1024]

If you are looking in to fail over, you'll need a router on both sides that has fail over capability.

What you'll ideally want is the router positioned with one WAN port going to your neighbors network and the other WAN port going to your cable modem (or whatever else the WAN end point is). Then just need to setup rules on the router for how to handle primary connection and backup.

At any rate, for wireless bridging, it just depends on what you are doing. Most likely, simple streaming a movie isn't going to stress a wireless bridge too much, unless you've got a crummy connection, for example a pair of regular wireless routers with omni-directional anntenas sitting in your houses a hundred feet away. If you are setting up some kind of more dedicated hardware bridge (like routers with directional antennas in windows pointed at each other or something), the wireless bridge is likely to be able to handle >50Mbps, which is way more than enough to handle stream video and sharing an internet connection (unless a fairly fat WAN pipe).

Obviously running a physical line is much better.

Are you talking actualy Cat5? Or are you talking Cat5e? Because there is a HUGE difference between the two (one is 100Mbps only, one is 1,000Mbps).

I ask in large part because so many people say Cat5 when they actually mean Cat5e.

 

[funkahdafi]

As for the failover part, if your router (or DD-WRT) allows to set route metrics, then it's as easy as setting two default routes with different mertrics. The first points to your ISP and has a lower metric (say 10) and the second points to the internet router of the other house, using a higher metric (say 100).

If the first route goes down, it'll automtically use the next available route. It will always use the route with the lowest metric as long as it is available.