Setting up 2 routers and a switch


Jun 13, 2009
I have an Internet connection through a cable broadband modem. I am wanting to connect it to a Linksys 5-Port switch then go from that switch to two routers. One is a wireless the other is not... both are NAT enabled. When i connect them this way i cannot see the internet through either router. Everything on the internal network can be seen but no internet will get past the switch.

What do I need to do to see the internet?


Won't work unless you pay for more than 1 IP address from your ISP.

Only one IP address is required, but the network needs to be properly configured. If the Internet IP address is dynamic (very likely based on the initial post), then the modem can't be connected directly to a switch. It has to be connected to a router with NAT capabilities.

Modem <---> Router 1 <---> Switch <---> Router 2 (can also be connected directly to Router 1)

This way Router 1 will provide access to the Internet. The Internet connection on Router 2 requires a static IP address and it's default gateway has to be Router 1. As long as routing is properly configured, it will work just fine. I've had a similar setup (with added complexity) for several years.


Router 1
LAN IP address
NAT range -
Internet IP address: Dynamic (provided by the ISP)
Route traffic to network mask to (the other router) or use dynamic routing (RIP has to be enabled on both routers)

Router 2
LAN IP addres
NAT range -
Internet IP address: IP address (connected to Router 1 or the switch)
Gateway IP address: (Router 1 IP address)
Even though you have a static IP address, you still need to connect a router to the modem, not a switch. The problem is that a switch doesn't do NAT and you absolutely need one to translate the single Internet IP address to multiple internal IP addresses.

What you're trying to achieve is very similar to what I have, but my setup is a bit more complex due to a corporate VPN. In your setup, you need to specify the IP address of the DNS on both routers if they are DHCP servers.


Apr 26, 2014
I am trying to do a similar thing. My modem is connected to isp via fiber optic cable. And the modem itself has 4 ports. Port No.1 is connected via ethernet to wifi router which gets bogged down with various connections from my family of 8. So I decided to connect another wifi router to Port No.2 and use that personally for torrents etc so the household load is divided between two routers. But when I try to connect it it doesn't go through with the connection. Seems that only Port No.1 is accessible. Now I read here that having a primary router is absolutely necessary, but let's say I connect another secondary wifi router to the primary router that is plugged in Port No.1 and I torrent on the secondary one, wont it bog down the primary one anyways?
What I want is two separate machines, one for torrents, one for everything else. Or else a solution to torrent peacefully.


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