TP-Link ER5120 cannot access upstream devices

sifov81

Prominent
Feb 11, 2018
2
0
510
I have a ER5120 configured with dual WAN, WAN 1 is fed from a local router. WAN 2 is fed by a remote router over a Ubiquiti Point to Point link.

I know the 2 rotuers should be in bridge mode, but this is not possible - the remote router serves a business and I am connecting to it as it has much quicker internet than I can get locally. I can connect to the remote router login page via IP address, however I cannot connect to any devices connected to the remote router. Is there a way to fix this?

This image explains things better (hopefully) https://ibb.co/gcY6J7

Internet and load balancing seems to work without any problems, however I would like to be able access devices connected to the remote router (such as a NAS Drive, camera and the point to point UI)

Would appreciate any help as I am a newbie!
 
Solution
I am very surprised that works at all.

You can not use the same subnet on 2 different connection unless they are actually bridged. Say one of the machines is 192.168.1.50
How does your dual wan router know which connection this is really on.

It is hard to say what will happen in a configuration like this. There really are no rules because technically it is not allowed. Many times the device will prevent you from mis configuring like this.

You really need 3 different subnets. Say 192.168.1.x, 192.168.2.x for the wan connections and 192.168.3.x for your lan.

Doing this you should now be able to access the 2 networks from your third lan network. There of course will be no access FROM the 2 wan networks to each other and...
I am very surprised that works at all.

You can not use the same subnet on 2 different connection unless they are actually bridged. Say one of the machines is 192.168.1.50
How does your dual wan router know which connection this is really on.

It is hard to say what will happen in a configuration like this. There really are no rules because technically it is not allowed. Many times the device will prevent you from mis configuring like this.

You really need 3 different subnets. Say 192.168.1.x, 192.168.2.x for the wan connections and 192.168.3.x for your lan.

Doing this you should now be able to access the 2 networks from your third lan network. There of course will be no access FROM the 2 wan networks to each other and limited traffic going to your lan network.
 
Solution

sifov81

Prominent
Feb 11, 2018
2
0
510



Thanks bill001g. I have changed the subnet of WAN1 (as that involved the least work) and now the LAN and 2 x WANs are all on different subnets. I can now connect to all devices locally connected to the remote router. Thanks again for fixing this.

Strangely I still cannot connect to either of the Ubiquiti point to point devices from 'home', however I can connect to them if I am working at the business location. I am not sure why, but neither of the PTP devices appear in the DHCP tables of the remote BT home hub router. Is there any way to make the PTP web os accessible from ‘home’?