cable modem and multiple router setup

devsk

I have a motorola surfboard modem (referred as MOTO) which I want to use as a wireless router in one part of the house. This is connected to internet through comcast cable.

It is connected (wired) to a netgear wireless router which serves the other part of the house.

The MOTO has 192.168.100.1 as its IP, and its DHCP leases out 192.168.100.2-50. The netgear has 192.168.100.3 on wan side from MOTO and its LAN side IP is 192.168.0.1. Netgear leases from 192.168.0.1-50.

The machines behind netgear can see all machines behind MOTO (ping and ssh works) but the machines behind MOTO can not ping anything on 192.168.0.X subnet.

I know I need to add a route to 192.168.0.0/24 network on the MOTO to use 192.168.100.3 as the default gateway but I can't find a setting to setup such a route.

Any ideas how I can achieve this? I want all my computers to be able to freely see and reach each other. I thought this would be very typical and trivial setup for largish homes, but its a pain to set it up correctly.

MacGyver031 · Posted: Fri Oct 19, 2012 1:26 pm Post subject:

What you are trying to do is impossible.

I would suggest that you deactivate dhcp-server on Netgear and use the first LAN port to connect to MOTO.
_________________
Sincerely your
Joanand K.

MacBook Pro 5.1: 2.4GHz Core2 Duo, 4096MB, 500GB, NVidia 9400/9600 M GT
Gentoo, Kernel 3.4.9, XOrg, Fluxbox.

devsk · Posted: Fri Oct 19, 2012 4:48 pm Post subject:

MacGyver031 · Posted: Fri Oct 19, 2012 5:40 pm Post subject:

The problem is that the Netgear router is designed to route packets from WAN to LAN. The otherway can only be done by assigning WAN:port -> LAN:port.

If you would like to send packets freely, then you need a gateway not a router.

What I have suggested is to use your Netgear as a switch and wlan accesspoint, while leaving your MOTO as the default gateway. You will achieve what you want, but you will have only one network. I have done this with two (D-Link and Netgear) "quasi routers", quasi because I do not use the routing part.

There is an other way: If you get sources and can build firmware for your Netgear, then you could use ip-forwarding WAN-port to LAN port and achieve what you have asked in the first place.
_________________
Sincerely your
Joanand K.

MacBook Pro 5.1: 2.4GHz Core2 Duo, 4096MB, 500GB, NVidia 9400/9600 M GT
Gentoo, Kernel 3.4.9, XOrg, Fluxbox.

devsk · Posted: Fri Oct 19, 2012 6:31 pm Post subject:

Simba7 · Posted: Fri Oct 19, 2012 10:14 pm Post subject:

I have a setup similar like this.

Basically:

Cable Modem -> Server/Router (My Dual P3) (eth0)
Server/Router (eth1) -> 8 port switch
2 AP's (connected through LAN, not WAN) -> Switch

Just make sure you disable DHCP on the access point(s). The server/router acts as a DHCP server. So the AP(s) are just that.. AP(s).. and do no actual routing.

I am curious on what kind of cable modem you are using. Usually the cable modem issues a public IP address, not a private one.

devsk · Posted: Sat Oct 20, 2012 12:01 am Post subject:

devsk · Posted: Sat Oct 20, 2012 3:58 am Post subject:

Ok. I moved netgear into "switch mode". I am getting DHCP assigned addresses over 192.168.100.x subnet from MOTO when wired to netgear. Wireless computers don't get any IP. Any ideas why?

devsk · Posted: Sat Oct 20, 2012 4:03 am Post subject:

Seems like laptop wasn't running dhcp client daemon for some reason. Things look good! This is exactly what I needed. A single network for my whole home.