ZyXEL Communications ZyWALL 2 Series User Manual

Page of 614
ZyWALL 2 Series User’s Guide 
VPN Screens 
14-5 
Table 14-2 VPN Rules 
LABEL DESCRIPTION 
Remote IP 
Address 
This is the IP address(es) of computer(s) on the remote network behind the remote IPSec 
router. 
This field displays N/A when the Secure Gateway Address field displays 0.0.0.0. In this 
case only the remote IPSec router can initiate the VPN. 
The same (static) IP address is displayed twice when the Remote Address Type field in 
the Edit VPN Rule (or Manual Key) screen is configured to Single Address.  
The beginning and ending (static) IP addresses, in a range of computers are displayed 
when the Remote Address Type field in the Edit VPN Rule (or Manual Key) screen is 
configured to Range Address
A (static) IP address and a subnet mask are displayed when the Remote Address Type 
field in the Edit VPN Rule (or Manual Key) screen is configured to Subnet Address.  
Encap. 
This field displays Tunnel or Transport mode (Tunnel is the default selection). 
IPSec 
Algorithm 
This field displays the security protocols used for an SA.  
Both AH and ESP increase ZyWALL processing requirements and communications 
latency (delay).  
Secure 
Gateway 
Address 
This is the static WAN IP address or URL of the remote IPSec router. This field displays 
0.0.0.0 when you configure the Secure Gateway Address field in the Edit VPN Rule 
screen to 0.0.0.0. 
Edit 
Click Edit to edit the VPN policy.
 
Delete 
Click Delete to remove the VPN policy. 
 
14.6 Keep Alive 
When you initiate an IPSec tunnel with keep alive enabled, the ZyWALL automatically renegotiates the 
tunnel when the IPSec SA lifetime period expires (see section 14.13 for more on the IPSec SA lifetime). In 
effect, the IPSec tunnel becomes an “always on” connection after you initiate it. Both IPSec routers must 
have a ZyWALL-compatible keep alive feature enabled in order for this feature to work. 
If the ZyWALL has its maximum number of simultaneous IPSec tunnels connected to it and they all have 
keep alive enabled, then no other tunnels can take a turn connecting to the ZyWALL because the ZyWALL 
never drops the tunnels that are already connected. Your ZyWALL model can support 5 simultaneous IPSec 
SAs.