[ale] IPSec question

[Stephan Uphoff]

> Does IPSec work behind firewalls and NAT devices.  I want to use it to
> connect to our home office from remote but when I go into datacenters
> 99.9% of the time I get an address that is private and behind a NAT
> Firewall.

No this won't work. (Unless you have control over the NAT device
and can forward a UDP port and a an IP protocol)

However you can layer things.
First go through the firewall using for example PPP over UDP.
( You can do PPP over TCP ... but I don't like layering 
retransmission protocols - there are also tons of other tunneling
solutions around)
Configure your tunnel to send probe packets or the NAT device might
decide that your UDP/TCP session is over and delete the mapping.

Then you add IPSEC to your link.

	Stephan