[c-nsp] PPPoE pass through over router

[Tseveendorj]

Hello,

I have configured NAS on my network but I need to configure network 
PPPoE over Routed network. Topology looks like below.


PC1 >>>>   Cisco 871 router1 >>>>>> NAS <<<<<< Cisco 871 router2 <<<<<< PC2

Is there anyway to configure PC1 and PC2 make PPPoE connection over 
Cisco 871 router1 and router2 to NAS ?

How to configure Cisco 871 routers for PPPoE pass through.

Sincerely
Tseveen.