[IPCop-user] Accessing red subnet from green subnet

[Matt M. <ma...@ma...>]

Hey all,

I've been playing with ipcop for a few weeks and finally encountered a
problem that I can't seem to find a solution to in the archives or on
Google...

I have a reasonable working knowledge of linux and networking--enough to
get myself into trouble, but not always enough to get myself out of it,
so please keep that in mind....

My primary question is about accessing the web interface of my DSL
modem--I use PPTP to dial my DSL modem and I can connect and access the
web just fine. However, I can't access the web interface for the modem
from the green network (I have a standard red + green setup).
I have a speedtouch home that's been hacked to be a speedtouch pro.
The green interface is set to IP address 10.0.0.1, netmask
255.255.255.0. The IP of the modem is 10.0.0.138. I can ping 10.0.0.1
from another computer on the green network, and I can ping 10.0.0.138
from the ipcop box, but I can't ping 10.0.0.138 from another computer on
the green network.  Any ideas on the cause of this? I saw something in
the archives about there being a rule to drop packets directed at the
red interface, but nothing on how to allow some packets through.

This is sort of another question but ties into the first. I was
originally trying to connect using DHCP spoofing with this modem--that's
why I did the speedtouch pro hack. This worked fine and in this
configuration I COULD access the web interface for the modem. However,
I found the DHCP spoofing method to be unreliable--if the modem went
down the ipcop box would sometimes end up with a private IP and it would
take some massaging to get the public IP passed through the modem to
ipcop again. PPTP is working fine for me, but for the sake of
curiosity, I'm wondering if there's a way to solve this problem, or if
someone could explain in detail what causes this problem? I think it
has to do with the delay of the modem in acquiring an IP to pass
through, and it assigns a private IP to ipcop in the interim, but this
IP is supposed to have a short lease (60 seconds) and ipcop was being
assigned a two hour lease.  I don't really understand why this is 
happening, however.

Referrals to online documentation or other venues of information are 
also welcome.

Thanks in advance, and Merry Christmas!!

Matt