2 Routers, A VPN, and DMZ... Oh my

Let say I have 2 routers and one internet connection (DSL).

One router (Router A) is connected to the DSL modem and controls the LAN and internet firewall for most of the facility.

Now I have Router B which is only controlling a few specific computers on another LAN and uses a VPN to connect to another facility

I need to have both connected to the internet but I can not put router A's LAN traffic on Router B (long story, polictal BS). Can I make Router B the DMZ on Router A and still have the VPN work? In otherwords, will the VPN from Router B function properly inside the DMZ of router A. What little I know about a DMZ is it has free unrestricted access to the WAN port and there is nothing in it's way.

I know the easier way would be to flip the routers so the one with the VPN is connecte directly to the modem, but we can't do that. We can not have LAN A's traffic passing through that VPN router at all.

 

Can you setup a VLAN with RouterA to divide RouterB's IP address\traffic from the other side of your network?

Not sure what type of routers you are using, so I don't know their capabilities.

 

I am curious if you resolved this as I have a very similar issue.

I am connected behind 2 routers as you mentioned and would like to setup VPN. I live in a remote area and I connect with WiFi through a priviate LAN to my ISP. I do not have control of the router that is connected directly to the internet (router A), but could request my ISP to assist if needed.