On Mon, 21 Feb 2000, Chan Yiu Wah wrote:

> LAN A (202.66.33.0) users can  access the ROUTER-A and ROUTER-B, but cannot
> access the user in LAN-B (e.g. ping 202.66.50.105).  The vice versa as the 
> user in LAN B.

I hate to say this, but now that you've gotten ppp to work, does the
"unnumbered interface" thing work any better? That is, try now to use
the ethernets ip addresses as the endpoints of the ppp link.
 
> If I login at LAN-A and tried to get file from ROUTER-B, there is message
> 'ppp_deflated exceed mru (1508 > 1504)' appeared on the console of ROUTER-A.

I seem to recall filing a PR on that. This is with "deflate", right?
Maybe BSD Compression would work better. Try "deflate 0 bsdcomp 9"
(use minimal BSD compression).