How best to bridge two LANs?

[rhythmdawg]

Hi

I'm new to home networking, but the problem I have is that I have to LANs (192.168.1.x and 192.168.2.x) but I don't know how to bridge or route network traffic between them, so if I'm on one LAN I can reach the other.

The router for my 1 LAN is an ASUS RT-AC3100 which handles all computer networking and the router for my #2 LAN is my Internet/Cable router from my ISP and handles A/V and Security devices. My #1 LAN router handles all routing tasks and I've disabled routing services on my #2 LAN router. I also have a Cisco SG300-10 managed switch on the #1 LAN that supports VLANs.

At this point I don't know if I should try to create static routes between the 2 LANS using my #1 LAN router, or try to create VLANs or routes using the switch.

My goal is to be able to access devices on #2 LAN from devices on the #1 LAN, but when it comes to routing I'm lost. Any starting advice or tutorials would be most welcome.

Thanks and take care,
Shayne

 

[don_bidyre]

You say that you’ve disabled routing on the LAN2 router.

In this scenario, both routers would need to be able to route traffic (that’s their job), indeed the LAN2 router would be the most relevant router.

The LAN1 router would by default route all traffic not intended for LAN1 to its default router (LAN2), which in turn would by default route all traffic not intended for LAN2 to the Internet.

So what you need is a routing rule in the LAN2 router to forward traffic intended for LAN1 to the LAN1 router.

How you do that will be specific to the device you are using.

It’s also worth noting that you probably have a firewall enabled on the LAN1 router which may impact your ability to communicate to devices on LAN2 if any of the traffic requires a session to be opened from LAN2 into LAN1 (most default home device firewalls should allow sessions to be opened in the other direction).

 

[dosborne]

If you want all devices on both subnets to be able to access each other, you could go to a single subnet. No routing table entries required.

 

[don_bidyre]

A single subnet would involve a wholesale network redesign as there is currently a router between the two networks! I assume that this design is intentional to keep a level of isolation between the two sets of devices.

One thing that has been worrying me about this setup is the comment about the routing services being turned off at the LAN2 router; does that mean that its operating purely as a modem? Is the LAN1 router using an External ISP provided IP on its LAN2 facing interface?

If so, that will never work as the LAN1 router will be routing all traffic not for LAN1 out to the ISP.