Home Network with two routers

home-networking

My home network was using a linksys WRT54GL in the "traditional" – WAN port is hooked to the DSL modem, once of the ports on the linksys goes to another switch and most of the computers in the house are wired to that 2nd switch. Everything was using the default 192.169.1.x subnet, so it looks like:

                    Wireless Devices
                           |
 [Modem] <-> [Linksys]  <->      [Switch]
                            |                          |
                     Computer1         Computers

Last week, I upgraded my internet connection, and the modem is now included in the router – it's a 2wire, which also does DHCP, etc. that uses 192.168.2.x. The network now looks like:

                                                                                      Wireless Devices (x.x.1.x)
                                                                                                    |
 [2Wire x.x.2.1] <-> [Switch]  <->   [Linksys - WAN=x.x.2.2, LAN=x.x.1.x ???]
                                       |                                                             |
                          Computers (x.x.2.x)                                Computer1 (x.x.1.x)

2Wire is now the DHCP server, and DHCP on the linksys is disabled.

Is it possible to continue to use 192.168.1.x for Computer1 and the wireless devices somehow? I tried connecting the WAN port of the linksys to the switch, and setting the router IP to .2.2, but that didn't seem to work.

The goal is to use the Linksys to serve DHCP to the wireless devices, and computer 1, while using DHCP from the 2wire for the rest of the computers. (The linksys allows me to specify the DNS servers, which means I can use opendns to restrict access to "safe" sites – wireless devices are ipods and Wii, and computer1 is also for the kids). 2wire doesn't seem to allow you to specify alternative DNS, it just passes on what it gets via PPPoE.

Is this possible, using the linksys firmware? Would it be possible with the DD-WRT firmware?

Best Answer

The Linksys and the 2Wire can do DHCP on their own LANs at the same time. Let the Linksys router receive an IP from the 2Wire, don't assign it. You don't need DD-WRT for this (although I'd use it anyway).


|--------------|                                              
|   2Wire      |              |---------------|   Wireless Devices
| WAN=(ext ip) |              |    Linksys    |   (x.x.1.???)
| LAN=x.x.2.1  |---[Switch]---| WAN=x.x.2.??? |     |
|--------------|       |      | LAN=x.x.1.1   |-----|
                       |      |---------------|     |
                       |                            |
            Computers (x.x.2.???)                 Computer1
                                                  (x.x.1.???)

In this setup, both the 2Wire and Linksys have DHCP on. The "???" means it receives a dynamic assignment from its DHCP server: Linksys WAN and Computers get it from 2Wire LAN, Wireless Devices and Computer1 gets it from Linksys LAN. You could pretty much just reset the Linksys to its defaults, then configure it with a LAN address of x.x.1.1 and plug it in. LAN DHCP is on by default. WAN will receive a dynamic IP by default (from 2Wire).

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