Computer Router into another computer router

[Scott Shepherd]

I think I can do this, I think I have done it at home in the past and it worked, but I wanted to check.

I sublease space, and with that, comes access to the internet. They have a DSL router. I want to setup a office network for us, but I don't want our stuff seen by them, on the network, plus, and the real limiting factor, is that we are only allowed one port on that router.

So can I get a new router, plug it into that one port we have, and then plug all of our stuff in that, and then setup our network from that point?

That'll work, won't it?

[Brad Wood]

you will need a crossover cable, or the ports on the two routers will need the ability to reverse the pinout in the software (often called an uplink port).
you could also put a small cheap switch between the two routers. A little four port Netgear switch is pretty cheap.

Also, you will want to find out what internal IP scheme the rest of the building is using so you can pick a different one. Chance are they are using 192.168.0.0 with a 255.255.255.0 mask. So, you would want to use something like 192.168.1.0 with a 255.255.255.0 mask. You want to stick with 192.168.x.x, or 10.1.x.x because these are reserved private IP ranges that won't get routed on the public internet (thats a good thing)

[Karlan Talkington]

I would recommend that you get a router with a decent firewall or inject a firewall between your router and the rest of your network.

Also know that because your leasor "owns" the upstream, there is nothing to stop him from putting a packet sniffer on the line to listen to your outbound traffic (traffic from your router up through his dsl router)

What's to stop you from requesting your own line? (other than added cost)

[Scott Shepherd]

Thanks, not quite as simple as adding a new line. We sublease and we have limited ability to provide documentation to the providers, which they like to see, apparently.

Not worried about them packet sniffing at all. They are low tech people and I don't do anything online I'd worry about. I mainly just want to start doing some network things with computers that are already here, just not connected to each other. I have shared some things as a test, but it opens it up to be shared by them as well, which I don't want. I would like to use a single printer, and some other devices, hence the desire to network.

Thanks for the info, I'll have to look at things next time I'm out.

[Jim Becker]

As previously stated, you can put another router/firewall behind the "house" router/firewall, but also as stated it's a good idea to set up your own IP range. Most routers default to EITHER 192.168.0.1 or 192.168.1.1, depending on the manufacturer. My Linksys and Dlink devices defaulted to the later. I don't remember what my Apple device defaulted to, but I believe it was also the latter.

[Rich Lightfoot]

It can be done BUT doing NAT twice, once for your router, once for theirs, can sometimes cause strange issues mostly with actual internet communications. You didn't mention if you wanted every computer to have internet access or if you just wanted to have file and printer sharing. If they all need access then I would try another router first just because it's easy and if any issues turn up move on to alternatives. On the other hand if only one computer needs access then I would focus on securing that particular system with a software firewall and a security policy, add a second NIC and drop in a switch and network your machines with a protocol other than TCP/IP like IPX.