ZyXEL Communications P-334WT Support Notes page 171

2. In remote side, generally speaking, most VPN clients will bind PPP/Ethernet adapter's dynamic IP address to IPSec
automatically . The only thing you need to concern is to specify the interface you want to apply IPSec/VPN correctly.
The rest parts are similar with that in static cases.
3. Afterward, the VPN connection can ONLY be initiated from dynamic side to static side in order to update its
dynamic IP to the static side.
4. In peer side, Are you using Win2K built-in IPSec?
automatically for you. You have to obtain your dynamic IP address and then go back to IPSec configuration to setup
your current IP address.
P-334WT dynamic WAN IP v.s. peer side static IP
In this case, W2K won't capture the dynamic IP address