Topic: One Cable Modem > 2 Wireless Routers?

[Fatah Ruark (aka MIKE B)]

Not "Computer Recording" but this is the closest place for this question.

One of the computers in my house has an old wireless card and doesn't play well with encryption on my new router. I still have my old wireless router and want to set up my cable modem to go into both routers. So, basically one cable modem into 2 seperate wireless networks.

Not too sure how to set this up. Would I need to get some sort of hub or switch?

The cable modem only has 1 network cable out of it.

What would I need to do this?

Here's a diagram of what I want to do:


                                                                                    / New Wireless Router (Belkin Wireless N)
Cable > Cable Modem > Network Cable> ?(Network switch?)  <
                                                                                    \ Old Wireless Router (Linksys WRT54GL)


Hopefully that all makes sense. Thanks.

[newscane]

Here's one way to do it (I think).  Run a cable from the modem to the Belkin (into its WAN port).  Set that router to hand out addresses in the 192.168.1.x range, for example.  Run another cable from one of the LAN ports on the Belkin to the WAN port on the Linksys.  Set up the Linksys to hand out addresses in another range, 192.168.5.x, for example.  That might work.  I base this on the fact that my DSL modem is also a "router" of sorts, and hands out addresses in the 192.168.1.x range.  So I had to set my Linksys router to work in the 192.168.5.x range.

[Fatah Ruark (aka MIKE B)]

Cool. I'll give that a try, although I think I may like to have each router running independently. That way if one goes on the fritz, everyone can just use the other network until I get home to iron things out (my roomies aren't good with computers).

I'm taking a Networking class that starts in a few weeks. At the very least I can learn how to do this then.

[newscane]

Cool. I'll give that a try, although I think I may like to have each router running independently. That way if one goes on the fritz, everyone can just use the other network until I get home to iron things out (my roomies aren't good with computers).

I'm taking a Networking class that starts in a few weeks. At the very least I can learn how to do this then.

Just did a Google Shopping search, didn't see many network switches per se for low prices.  These days, switches tend to be big things for large IT environments.  You could get a wired router, and plug both wireless routers into it.  I'm not sure how to set things up so that the computers can easily "switch" between the two networks, if your roommates aren't good with computers.  You'd need to make sure the wireless networking settings are automatic to allow the computer to switch between the two.  I still don't know how that would behave.

[Sebastian]

Connecting the two routers via ethernet *should* work, but you may have to disable the DHCP server on one of them and make sure they are in the same address range for them to be able to see each other. Some vendors use the 192.168.0.* subnet, some use 192.168.1.*, some use a subnet in the 10.* range by default. Also make sure the SSIDs on both routers are the same. You might have to enable ethernet bridging, too (if that's an option).

Possibly another solution... Have you tried the OpenWRT firmware for the Linksys router? It's basically a stripped-down version of Linux that lets you configure the router in every possible way.

[phanophish]

Why not just drop down the new router to encryption that is compatible with the old PC.  In the drawing you have above the 2 routers will both provide a wireless connection to the same network so regardless of how secure one of them is if the other runs no/weak encryption your overall network is not secure.

[Church-Audio]

Not "Computer Recording" but this is the closest place for this question.

One of the computers in my house has an old wireless card and doesn't play well with encryption on my new router. I still have my old wireless router and want to set up my cable modem to go into both routers. So, basically one cable modem into 2 seperate wireless networks.

Not too sure how to set this up. Would I need to get some sort of hub or switch?

The cable modem only has 1 network cable out of it.

What would I need to do this?

Here's a diagram of what I want to do:


                                                                                    / New Wireless Router (Belkin Wireless N)
Cable > Cable Modem > Network Cable> ?(Network switch?)  <
                                                                                    \ Old Wireless Router (Linksys WRT54GL)


Hopefully that all makes sense. Thanks.

You also have to remember that all interweb companies put a limit on how many ip addresses you can have at one time. Remember every active port on a router is one ip address.

PS. if the problem is one of your computers having an old network card maybe you should just buy a new one for that computer? they dont cost much personally I would never run wifi unless I had to. Its way to easy to hack. I have a wifi here but its very well protected and I only use it for my laptop. Everything else has a wire. And not only that but wifi is much slower then a wire.. MUCH slower.

[rastasean]

If four ports on a router isn't enough for you, wow. let me have a computer.
but
if four ports are not enough, I would look into getting a switch and just connecting that to the cable modem and forget about wireless. Just ask yourself how you survived without wireless before it was so popular.

[Sebastian]

You also have to remember that all interweb companies put a limit on how many ip addresses you can have at one time.

I don't understand this. Most ISPs will give you one IP address per dial-up (or DSL/cable) connection. And that's all you really need.

Remember every active port on a router is one ip address.

That is not correct. The number of open ports does not have anything to do with the number of IP addresses. You can have as many as 2^16 open ports per network address (IP address). And I'm sure you'll never reach that limit.

[Church-Audio]

You also have to remember that all interweb companies put a limit on how many ip addresses you can have at one time.

I don't understand this. Most ISPs will give you one IP address per dial-up (or DSL/cable) connection. And that's all you really need.

Remember every active port on a router is one ip address.

That is not correct. The number of open ports does not have anything to do with the number of IP addresses. You can have as many as 2^16 open ports per network address (IP address). And I'm sure you'll never reach that limit.

I stand corrected. I was wrong.

Chris

[Sebastian]

Chris, I know what you meant (I saw it before you edited your post). Most ISPs will tell you you can't connect more than a given number of devices to the internet. But all IPs your router gives out via DHCP are a private network. With a correctly configured router/firewall, there is no way for an ISP to prove that you have more than the allowed number of devices. The only thing they could see are the MAC addresses of the devices' ethernet interfaces. But they will have a hard time proving you're in fact using more than the allowed number of computers at the same time. It's just a scare tactic...

[rdfager]

Chris, I know what you meant (I saw it before you edited your post). Most ISPs will tell you you can't connect more than a given number of devices to the internet. But all IPs your router gives out via DHCP are a private network. With a correctly configured router/firewall, there is no way for an ISP to prove that you have more than the allowed number of devices. The only thing they could see are the MAC addresses of the devices' ethernet interfaces. But they will have a hard time proving you're in fact using more than the allowed number of computers at the same time. It's just a scare tactic...

There are a few methods of detecting the number of machines going through NAT.  The most common ways involve looking at the TCP sequence numbers or using sFlow.

I've never heard of an ISP actually doing this.  I doubt that many, if any, do.

Here's a little more info -http://yro.slashdot.org/article.pl?no_d2=1&sid=03/04/24/0119209

Sorry for the thread hijack.

I'll add my $.02 on your question:

First, I'm not sure why you want to do this.  Having one wireless network with no encryption makes using encryption on the other wireless network pointless, unless you're setting up a firewall between the two networks and putting the unencrypted AP on a DMZ or something.  Your network is only as secure as the least secure AP.

Second, most ISPs will give you only one IP address.  You can get more but you'll probably have to pay for them.  That's why people use these routers.  The routers perform network address translation (NAT) to allow you to have a private network in your home with multiple computers.  The routers make all of these computers appear to be coming from the single address that your ISP assigns you.  You'll probably not be able to connect two routers to your cable modem, even if you put a switch/hub between the routers and the cable modem because only one of the routers will receive the IP address from your ISP.  You could probably connect one of the routers to the cable modem and then connect the second router to the first router.  However, then if the first router dies, your network will be down and you may run into problems because you'll be going through NAT twice.  Doing NAT twice will break a few protocols.

If you really want to do this, I'd recommend asking your ISP if they will give you a second IP address. Then you should be able to connect both routers to your cable modem, though you'll probably need to put a switch or hub between the routers and the cable modem as the cable modem probably only has one ethernet connection.