Dual Router Network Setup Issues

[TramVanCollision]

Hi everyone,

A long-time lurker, first time poster here; thanks for everyone's past contributions to these forums, they've been invaluable to me over the years!

I recently decided to complicate my home network a little by adding a second router into the mix.

I'm doing this primarily because the additional router supports a proprietary VPN service to link to a telematics network but also because it should enable me to use a cellular connection as a backup WAN.

These forums contain various threads that refer to setups that use dual routers, double NAT & dual WAN and I've tried to follow the advice within them but I can't get it to work, my head is now hurting and I realise that I need some help!

I've attached a diagram that shows the dual router network design that I arrived at.

I have tested the WAN connectivity on Router A via a direct LAN Ethernet connection (192.168.50.0/24) and all is well but clients connected to the LAN behind Router B (192.168.1.0/24) can't access Router A or the Internet beyond it.

Please could one of your very lovely and helpful people suggest where I might be going wrong?

As you can see from the diagram, once (if) I get the underlying networking working I's then like routes from the LAN (192.168.1.0/24) to an IPSec VPN client on Router B and the Peplink VPN service on Router A.

 

[ColinTaylor]

I have tested the WAN connectivity on Router A via a direct LAN Ethernet connection (192.168.50.0/24) and all is well but clients connected to the LAN behind Router B (192.168.1.0/24) can't access Router A or the Internet beyond it.

I suggest you go back to basics and test a simple out-of-the-box setup for router B. So make sure you have not disabled NAT on router B, and delete all static routes as they are not needed.

 

[TramVanCollision]

I suggest you go back to basics and test a simple out-of-the-box setup for router B. So make sure you have not disabled NAT on router B, and delete all static routes as they are not needed.

Hi Colin and thanks for the super fast response!

I wasn't sure about the need for the static routes tbh! I've now deleted them but the issue persists.

If I remove Router A from the network and run the PPPoE WAN direct to Router B, then clients connected to the LAN behind Router B can access the Internet without any issues.

When Router A is introduced and I only change the WAN from PPPoE to Static IP (as shown) on Router B, then they can no longer reach the Internet or Router A.

NAT is enabled on both Router A & Router B.

 

[ColinTaylor]

When Router A is introduced and I only change the WAN from PPPoE to Static IP (as shown) on Router B, then they can no longer reach the Internet or Router A.

Does Router B's GUI show that it has connection to the internet (Network Map > Internet status)?

Maybe try changing Router B's "WAN Connection Type" to Automatic IP rather than Static.

 

[TramVanCollision]

Does Router B's GUI show that it has connection to the internet (Network Map > Internet status)?

Maybe try changing Router B's "WAN Connection Type" to Automatic IP rather than Static.

Thanks again Colin.

No, Router B shows the WAN as disconnected.

Yes, I have tried both Static and Automatic IP (with reservation) for the Router B WAN connection but the results are the same.

I wondered if it were some kind of DNS issue but I can't ping between the networks or to the Internet either, so that rules this out.

I'm beginning to suspect that maybe there is something about Router A that isn't functioning as I would expect; that maybe the routing between the LAN & WAN ports of the PepWave device aren't set up correctly.

 

[ColinTaylor]

With Router B setup the way it is and the WAN set as Automatic (DHCP) any traffic from it should be indistinguishable from any other DHCP client on the 192.168.50.0/24 network.

If the Asus can't resolve DNS requests, it will assume there is no internet connection. So, if you're blocking Microsoft's sites on the PepWave for example this could be a problem. What firmware are you running on the Asus? With Merlin's firmware there are more options than in stock.

With the Asus WAN set for DHCP does it get an IP address from the PepWave, e.g. 192.168.50.2? If not look in the Asus' System Log for WAN errors.

 

[TramVanCollision]

Well, I've now cracked it Colin.

It appears that the default network of the PepWave router doesn't allow any routing between the Ethernet LAN & WAN ports!

To set the routing up you have to create a new VLAN, connect the Ethernet LAN ports to this and then designate them as "Access" ports.

Once I did this the whole thing sprang into life and is working as expected.

Now I just need to establish a PepVPN from this PepWave device to the remote one, I'm sure that'll be a walk in the park!

Thanks for all your help and sorry to have wasted your time!