Before You Begin - ZyXEL Communications P-661HNU Manual

If the remote secure gateway has a static WAN IP address, enter it in the Secure
Gateway Address field. You may alternatively enter the remote secure gateway's
domain name (if it has one) in the Secure Gateway Address field.
You can also enter a remote secure gateway's domain name in the Secure
Gateway Address field if the remote secure gateway has a dynamic WAN IP
address and is using DDNS. The ZyXEL Device has to rebuild the VPN tunnel each
time the remote secure gateway's WAN IP address changes (there may be a delay
until the DDNS servers are updated with the remote gateway's new WAN IP
address).
Dynamic Secure Gateway Address
If the remote secure gateway has a dynamic WAN IP address and does not use
DDNS, enter 0.0.0.0 as the secure gateway's address. In this case only the
remote secure gateway can initiate SAs. This may be useful for telecommuters
initiating a VPN tunnel to the company network (see
for configuration examples).
The Secure Gateway IP Address may be configured as 0.0.0.0 only when using
IKE key management and not Manual key management.
Finding Out More
See Section 16.6 on page 229

16.1.3 Before You Begin

If a VPN tunnel uses Telnet, FTP, WWW, then you should configure remote
management (Remote MGMT) to allow access for that service.
P-661HNU-Fx User's Guide
for advanced technical information on IPSec VPN.
Chapter 16 VPN
Section 16.6.11 on page 237
219