Have two networks, A and B where I cannot access router on B

[ptrinh1979]

Hey everyone,

I have an interesting problem where I have two networks A and B where I am no longer able to access the router on B although it is serving IPs in its own subnet. Before I actually state the question I have in my mind, here is some background information.

So here is my setup:

I have a Linksys WRT54GS running DD-WRT on 192.168.1.1 serving IPs in this subnet. I will refer to this as Router A and therefore Network A.

I also have a Buffalo WHR-HP-G54 running DD-WRT on 192.168.11.1 also serving IPs in this subnet. I will refer to this as Router B and therefore Network B.

I configured router B's wireless radio to act as a client to Router A, as if Network A is Router B's WAN connection. The reason I did this is because I am unable to run some cable in between the two devices.

So, for some reason, I am unable to access Router B from a computer that is on Network B, but I AM able to access Router A, although I am NOT on Network A at all. Does anyone have any ideas that may explain this?

The reason this is an issue for me right now is because I need to be able to access my laptop which is a wireless client to Network A, and vice versa. In hindsight, I may have been better off to have disabled all DHCP serving features on Router B so that it would act as a switch and let Router A handle DHCP duties for both my networks. I actually tried to make this change by accessing the web setup GUI on Router B and ran into the above symptom.

Any assistance, comments, feedback, and/or correction to my mindset is greatly appreciated!

-ptrinh1979

 

[jdabbs]

My guess is that you configured Router B to wirelessly connect to A, but this bridged the LAN connections together and does not pass through the WAN of B. That leaves a flat network with two subnets unable to communicate with each other. Which subnet you would be able to access is dependent upon which subnet the leased/static IP is in.

I suggest keeping the bridge and disabling DHCP on Router B. If you need access to Router B's config, give it an LAN IP in A's subnet but not part of the DHCP scope.

 

[Vla]

Hi ptrinh1979,

I believe the problem is that Router B is configured to use NAT, thus all the devices on the Network B are hidden behind the NAT for the devices of the Network A. Try switching your Buffalo device to Routing mode instead of NAT mode (Linksys devices use this terminology if I'm not mistaken, so just look for the similar setting in Buffalo.

 

[Vla]

upd: just noticed that you use DD-WRT for the Buffalo as well. In this case you'd search for the "internet connection" setting and switch it to "disabled". You may also need to add some static routing rules on both devices depending on the config...