ZyXEL Communications ZyWALL 110 Series, User Manual, Page: 290 / 562

Chapter 20 IPSec VPN
ZyWALL 110/310/1100 Series User’s Guide
290
Authentication Select which hash algorithm to use to authenticate packet data in the IPSec SA.
Choices are SHA1, SHA256, SHA512 and MD5. SHA is generally considered
stronger than MD5, but it is also slower.
The ZyWALL and the remote IPSec router must both have a proposal that uses the
same authentication algorithm.
Perfect Forward
Secrecy (PFS)
Select whether or not you want to enable Perfect Forward Secrecy (PFS) and, if you
do, which Diffie-Hellman key group to use for encryption. Choices are:
none - disable PFS
DH1 - enable PFS and use a 768-bit random number
DH2 - enable PFS and use a 1024-bit random number
DH5 - enable PFS and use a 1536-bit random number
PFS changes the root key that is used to generate encryption keys for each IPSec SA.
The longer the key, the more secure the encryption, but also the longer it takes to
encrypt and decrypt information. Both routers must use the same DH key group.
Related Settings
Zone Select the security zone into which to add this VPN connection policy. Any security
rules or settings configured for the selected zone apply to this VPN connection policy.
Connectivity Check The ZyWALL can regularly check the VPN connection to the gateway you specified to
make sure it is still available.
Enable
Connectivity Check
Select this to turn on the VPN connection check.
Check Method Select how the ZyWALL checks the connection. The peer must be configured to
respond to the method you select.
Select icmp to have the ZyWALL regularly ping the address you specify to make sure
traffic can still go through the connection. You may need to configure the peer to
respond to pings.
Select tcp to have the ZyWALL regularly perform a TCP handshake with the address
you specify to make sure traffic can still go through the connection. You may need to
configure the peer to accept the TCP connection.
Check Port This field displays when you set the Check Method to tcp. Specify the port number
to use for a TCP connectivity check.
Check Period Enter the number of seconds between connection check attempts.
Check Timeout Enter the number of seconds to wait for a response before the attempt is a failure.
Check Fail
Tolerance
Enter the number of consecutive failures allowed before the ZyWALL disconnects the
VPN tunnel. The ZyWALL resumes using the first peer gateway address when the VPN
connection passes the connectivity check.
Check this Address Select this to specify a domain name or IP address for the connectivity check. Enter
that domain name or IP address in the field next to it.
Check the First
and Last IP
Address in the
Remote Policy
Select this to have the ZyWALL check the connection to the first and last IP addresses
in the connection’s remote policy. Make sure one of these is the peer gateway’s LAN
IP address.
Log Select this to have the ZyWALL generate a log every time it checks this VPN
connection.
Inbound/Outbound
traffic NAT
Outbound Traffic
Table 107
Configuration > VPN > IPSec VPN > VPN Connection > Edit (continued)
LABEL DESCRIPTION