Sorry if this is off topic, I am going to be setting up a network soon and
need some ideas on the best way to set it up. The network topology is as
follows:
 One LAN, connected on Ethernet, and permanently connected to the internet,
with the gateway having a static IP address.
 The other LAN, about 1500km from the first, also Ethernet, but the gateway
connecting to the internet through a dial-up connection, and being allocated
any IP address from a range of IP addresses.

My questions are:
 - how do we ensure secure transmission over the internet section? With a
tunnel, the "gif" interface?
 - how do we allow packets through the gateway, especially when the one
gateway changes IP addresses every dialup?
 - we have only two public IP addresses, the two gateways. How do the
systems on each LAN address each other?

Any help would be greatly appreciated...

Bruce Martin.