dual wan network configuration help

[patjr]

In my home network I need to force certain devices to use specific ISPs.
The networks are currently configured as follows

ATT --> DSL Modem --> Linksys wrt-54g running tomato --> 192.168.2.0 sub-net

Comcast --> cable modem --> Asus AC-68U --> 192.168.1.0 sub-net

this configuration works fine but doesn't allow any devices to see the devices on the other sub-net which means no NAS access printer access etc...

In addition to the above I have a Raspberry PI with 2 wired Ethernet ports (one via a USB adapter) I hope to use as a router to connect the two 192.168 networks.

another thought is does tomato or ddwrt offer dual wan modes that you can force devices to specific wans instead of fail over and load balance?

I am very technical but this is beyond my network skills thanks in advance for all suggestions or guidance

 

[System Error Message]

why not just use dual WAN on asus and configure static routes for both subnets. In order for devices from one subnet to be able to see another they both must have either routes defined on all of the devices or use of a NAT between the 2 networks.

If you are using static routing than all devices that communicate between subnets require static routes configured. on the router you define 2 IP addresses for the subnets as gateways and create a route that defines the destinations and gateways. For example to get from x.1.0 to x.2.0 you need to make a route defined like this.
for subnet 1
destination 0.0.0.0/0 gateway x.1.1 (internet)
Destination x.2.0/24 gateway x.1.1
for subnet 2
destinatioj 0.0.0.0/0 gateway x.2.1 (internet)
destination x.1.0/24 gateway x.2.1

On windows command line using route print will show the routes and you can than add as you need.

Every device requires that route added and also on the router too (some routers add that route automatically). Devices between 2 subnets cannot see each other if their protocols rely on broadcasts and multicasts that are either L2 or IP based protocols that only communicate within the same subnet.

You could also NAT between them eliminating the need to configure the devices seperately. On some routers if the routes are there there is no need to configure the devices seperately. If you want to use 2 routers than both routers need to be linked and have each other subnet ip and route. If you configured it right you can access the printer of other subnet by using its ip address manually instead of trying to search automatically.

 

[patjr]

at this point I am leaning to configuring PFsense with dual wans and forcing traffic to specific wans based on ip range.....

I hear that's doable so a config like this

wan1 -+ +-- Linksys 192.168.1.x
| |
+ Pfsense ----|
| |
wan2 -+ +--asus 192.168.1.x

 

[System Error Message]

once you have pfsense just use your other routers as wifi APs and switches. PFsense can route traffic based on IP, you should be able to make the rules.

You could also have a selective DHCP server on pfsense (based on host) or seperate DHCP servers running on your wifi rouiters.