How do i connect 2 different networks?

By erilaurence ·
I'm tasked to link 2 networks. network A and B have their own routers to connect to the internet, basically just your average home dsl routers. the link between the two are wireless ap's. geographically, they are 5km apart. the problem isnt linking them actually, but how to make them see each other since each network is different, ie how can a host in network A ( gain access to a shared folder of a host in network B ( vice versa?

also, i want them to be able to connect on vlan/vpn (are they even interchangeable?) through internet, in case the wireless link goes down.

i thought of connecting the two networks to a linux router with 3 NICS, one for network A, one for the wireless AP and one for the internet, which will substitute network A's dsl router since this linux router will be placed at network A's location.

the thing is, im confused if i need to do this or just simply create a subnet. but, i dont know anything about subnetting and the equipment it requires. will i be able to subnet with the use of only 2 dsl routers and perhaps 2 unmanaged switches?

also, with regards to creating a linux router, will it be able to automatically generate its routing table or do i need to manually enter it so it will be able to connect the two networks?

this work may just be way over my head, but i want to at least give it a try because i really want to learn networking hands-on


This conversation is currently closed to new comments.

11 total posts (Page 1 of 2)   01 | 02   Next
| Thread display: Collapse - | Expand +

All Answers

Collapse -

Don't know much about Linux...

by cmiller5400 In reply to How do i connect 2 differ ...

But, you need some sort of layer 3 routing going on between the networks. What you are asking for is a very complex design that involves HSRP for when the wireless link goes down, it will open a VPN tunnel to the other site.

This is not for the inexperienced. Your best bet if you don't know what you are doing is to hire someone that does. It opens a big security hole if you don't do it right.

Collapse -


by erilaurence In reply to Don't know much about Lin ...

ok then, what if i make the network simpler, like just making them see each other instead of switching to vpn when the wireless link goes down. let's assume that the wireless link always work.

the wireless link between the two is a cisco wireless AP in bridge mode, so basically that's almost the same as having network B just right beside network A. what im racking my brains about is how to make the two networks see each other?

it's like i have 3 connections and i dont know how to interconnect the 3 of them, network-wise.

a simple way to go about this using a home dsl router is that network A plugs in to a lan port of the router, network B plugs in to another lan port of the router and the dsl modem plugs in to the wan port of the router. and i could just change all of network B's ip addresses into the same range as network A. But... i want to make the two networks as distinguishable from each other as possible.

i hope i dont sound too idiotic with my question

Collapse -

Linux Router/Firewall

by NormH3 In reply to How do i connect 2 differ ...

The only Linux router that I am familiar with is IPCOP although there may be others. I believe you will have to manually create the routing table for this to work properly.

Collapse -

I agree

by eylusion In reply to Linux Router/Firewall

Although I'm not sure how you would put both networks on a linux gateway if they are 5km apart. What I would do is first find out if the 2 dlinks or whatever have vpn tunneling capability built into them (unlikely). At which point I would suggest you purchase two business class routers, and then in turn setup a vpn connection between the two routers. After that setting up a route on each router would be simple, Router A(192.168.x.x) inspects a packet sent from local net for destination 10.x.x.x forward to interface vpn1, and vica versa, granted the routers would probably do this for you dynamically, but depending on the routers, i'm sure however you set it up, I don't think it would take you more than a few minutes to figure out just playing with the configuration.

Collapse -

wireless ap

by erilaurence In reply to I agree

there's a wireless AP link between the two, i assume that the AP will have a rj45 jack coming out from it which "carries" the whole network B. i am more concerned at how to make the two networks see each other using only either the two dsl routers, or with a linux router. the vpn can come later.

Collapse -

You NEED a router between them.

by cmiller5400 In reply to wireless ap

Where you have different IP's on each of the subnets, you NEED a layer 3 routing device between them. This device can be a router or a layer 3 switch.

Okay let's start from the beginning.

1. You want the 2 locations to have connectivity over the wireless link to each other. Connect the wireless AP to a router on each end. Configure router A to say that any traffic for 10.0.0.x goes over the wireless link on ethernet port blah. Configure router B to say that any traffic for 192.168.1.x goes over the wireless link on ethernet port blah. You can do this automatically with EIGRP if you use Cisco equipment.

2. You want the internet on the network. So plug in the connection from the DSL modem into an Ethernet port on the new router. Configure a default route that pushes all traffic it doesn't know where to send to be pushed out that port.

From what you have stated, I strongly recommend that you hire this out or you take some serious training. This is not a place for beginners to be messing around in.

Disclaimer: I am by no means a routing expert, but I have a general knowledge.

Collapse -

router = not dsl router?

by erilaurence In reply to You NEED a router between ...

so im guessing that i need to get a cisco class router for this job?

and thanks, you may not be an expert, but you're have way more knowledge in this than me and that helps:)

Collapse -


by cmiller5400 In reply to router = not dsl router?

A DSL modem/"router" does not have the capability's that you need to interconnect these two networks. You will need some sort of layer 3 routing (router or layer 3 switch) between the two if you don't want to change the IP addresses. Yes you will need some sort of business class router to do what you want.

I strongly suggest that you talk with a vendor to find out exactly what you want. There is no need to buy equipment that has way too many features. And the reverse as well, buy a router that doesn't do what you need it too.

Collapse -

This might be of help to you.....

Back to Networks Forum
11 total posts (Page 1 of 2)   01 | 02   Next

Hardware Forums