2 Routers (Separate Networks) with 1 Cable Modem Connection

[Scheizekopf]

I have Adelphia Cable Service. 1 Modem. I want to have 2 separate networks in my house. I already have 1 network (Router -> Switch -> 3 other Switches (1. 2comps & printer) (2. 3comps) (3. 1comp & printer).

I want to do Router -> Switch -> Switch -> 2 comps & Printer
and

Router -> Switch -> (1. Switch -> 3comps) (2. Switch -> 2comps & Printer)

Dont worry about all of the switches. I have a big two story house with the whole house networked.

Can I do this? Have 2 Routers with 1 Modem?

Thanks for all the help and comments.

 

[anotherguy159]

Do you want two physical or two logical networks?

If you want two logical it is just a matter of subnetting.

 

[XOR != OR]

Assuming you set it up correctly, that setup will work.



Seriously, as long as you present a single MAC to the modem, the setup should work

 

[Scheizekopf]

Do you want two physical or two logical networks?

If you want two logical it is just a matter of subnetting.

Two physical networks.
Example: 1st network as 192.168.1.1 and the 2nd network as 192.168.2.1


XOR != OR - I'm not sure exactly what you're saying. I'm asking how do I set it up. If I set it up correctly, then yea it should work but I'm not sure how to do it. And how would I give the modem one MAC address when there is 2 routers (2 MAC Addresses)?

 

[Scheizekopf]

hello?

 

[Phildeeze]

I would do it like this:

Modem----Router1-----Network1
.....................\
.....................Router2------Network2

So the second router's WAN port is plugged into one of the LAN ports on the first router. Make Router1's network 192.168.1.1 and Router2's network 192.168.2.2.

 

[Airborne]

Why use two routers? One router will suffice.

Modem -- Router -- interface A (first network) --- LAN A
\- interface B (second network) -- LAN B

 

[sigmend]

...........................Router1-----Network1
........................../
Modem----Router3
...........................\
.............................Router2------Network2

Maybe?
This would give you one MAC on the modem, and two different networks.

I am just prolly spewing shit

 

[Party2go9820]

Why use two routers? One router will suffice.

Modem -- Router -- interface A (first network) --- LAN A
\- interface B (second network) -- LAN B

That is definately the most elegant solution but will be kinda costly since few home routers have multiple interfaces.

Another option would be to get a managed switch and set up different VLANs behind a router.

 

[XOR != OR]

Why use two routers? One router will suffice.

Modem -- Router -- interface A (first network) --- LAN A
\- interface B (second network) -- LAN B

Yeah, 1 router, feeding out to two switches, which connect the rest of the network. Easiest and best way to do it.

Unless you want to keep the two network seperate. In which case, I'd make those two switches routers with firewalls. But that may be overly complex for this setup.

 

[Scheizekopf]

Yeah, 1 router, feeding out to two switches, which connect the rest of the network. Easiest and best way to do it.

Unless you want to keep the two network seperate. In which case, I'd make those two switches routers with firewalls. But that may be overly complex for this setup.

I want completely separate networks.

The easiest/cheapest way looks like:
modem -> router1 -> switch -> nodes
...................\
..................router2 -> switch -> nodes

That doesnt seem completely separated though. Am I wrong?

What about:

modem -> switch or hub -> router1 -> switch -> nodes
....................................\-> router2 -> switch -> nodes

 

[XOR != OR]

I want completely separate networks.

Ok, let's start from scratch, and you tell us why you need two seperate networks. There might be an easier solution to this.

 

[Phildeeze]

What about:

modem -> switch or hub -> router1 -> switch -> nodes
....................................\-> router2 -> switch -> nodes

That won't work unless your modem can handle more than one attached MAC address. A switch or hub is basically a multi-port repeater, so the modem would see both routers attached to it. Probably whichever one you attached first would work and the other network would be cut off from the Internet.

The easiest/cheapest way looks like:
modem -> router1 -> switch -> nodes
...................\
..................router2 -> switch -> nodes

That doesnt seem completely separated though. Am I wrong?

No, you're not wrong, but unless you're doing something really different, it should be seperate enough that the connection between the two nets won't matter. PC's on one network won't be able to see PC's on the other.

 

[Scheizekopf]

Ok, let's start from scratch, and you tell us why you need two seperate networks. There might be an easier solution to this.

Just to have 2 separate networks. One for a business (Security) and the other for testing and probably less security.

 

[lomn75]

In that case, Phildeeze's router layout is sufficient. Keep the business LAN behind both routers, use the first router as a DMZ of sorts for testing. There's no reason to keep the testing data inaccessible to the business side, so this is suitably segregated.