Here's what I have:
I have a modem dialup to work to get behind the firewall.
I have a broadband internet access (when it works).
Here's what I want:
My default internet access should be broadband. Only if I try to
access/receive from a box with IP starting of the format 172.x.x.x
(that'd be a company box behind the firewall) it should perform all
traffic for those via the dial-up.
DNS for the dialup isn't really an issue, but wouldn't hurt.
The company dialup is via NT RAS. I got it to work quite alright via PAP
but then all internet traffic runs via the dial-up which isn't so
great as I share the access with the rest of my family and their PCs.
Security is of course an issue as well, as I don't want to compromise
my company's firewall. I use an external modem and I plan to switch it
*off* whenever I don't use the access. Additionally, i should be able
to write a proper IPCHAINS or IPTABLES rule.