Thread: Routing two Subnets

I have two subnets which I am interested in connecting. I’ve read from beginning to the Linux Networking HOWTO, a few guides here on nixCraft, many forums posts, but have so far succeeded only in confusing myself.

Some basic network details:

Subnet A:
Network Range: 192.168.1.0/24
Gateway 1A: 192.168.1.1/255.255.255.0
Gateway Interfaces:
br0: 192.168.1.1/255.255.255.0
vlan1: 70.76.84.224/255.255.252.0
LAN Domain: tec.lan
Example Host 1A: perpetrator.tec.lan – 192.168.1.10/255.255.255.0
Example Host 2A: rapine.tec.lan – 192.168.1.11/255.255.255/0

Subnet B:
Network Range: 192.168.2.0/24
Gateway 1B: 192.168.2.1/255.255.255.0
Gateway Interfaces:
eth0: 192.168.1.145/255.255.255.0
eth1: 192.168.2.1/255.255.255.0
LAN Domain: tec.lan
Example Host 1B: ubuntu-01.tec.lan – 192.168.2.10/255.255.255.0
Example Host 2B: ubuntu-02.tec.lan – 192.168.2.11/255.255.255.0


I am trying to think of any further relevant details, but that seems to be it to me. If I forgot anything, please tell me.

Ok the question. WHAT do I type? (Explicitly!) And WHERE do I type it? In order to reach ubuntu-01.tec.lan, or ubuntu-02.tec.lan from perpetrator.tec.lan or rapine.tec.lan?

Note: I’m interested in using actuall ROUTES. I can already achieve results similair to this with either a NAT firewall, or with VPN.. but that’s not what I am interested in.

Thank you very much for your reads and help in advance! This seems like it should be a simple thing, but I am having incredible difficulty with this..

From what I have found out so far, I should need something like the following:

On Gateway 1B:

Code:

route add -net 192.168.1.0 netmask 255.255.255.0 gw 192.168.2.1 dev eth1

And on Gateway 1A:

Code:

route add -net 192.168.2.0 netmask 255.255.255.0 gw 192.168.1.1 dev br0

Any help would be appreciated!

Sorry for the delay on the reply, but I forgot to attend to my thread. I know I know, bad me!

Just an update.. I have it all working perfectly now. The correct answer was:

1. Tell the machines on Subnet B to use 192.168.2.1 as their gateway, and:

2. On Gateway 1A, configure a static route telling packets trying to reach 192.168.2.0/24 to use 192.168.1.145 as their gateway.

Code:

route add -net 192.168.2.0/24 gw 192.168.1.145

Thank you for your time.