ZyXEL Communications 50 User Manual
ZyWALL 50 Internet Security Gateway
VPN/IPSec Setup
23-15
23.5 Manual Setup
You only configure Menu 27.1.1.2 – Manual Setup when you select Manual in the Key Management field
in Menu 27.1.1 – IPSec Setup. Manual key management is useful if you have problems with IKE key
management.
in Menu 27.1.1 – IPSec Setup. Manual key management is useful if you have problems with IKE key
management.
23.5.1 Active Protocol
This field is a combination of mode and security protocols used for the VPN. These parameters have been
discussed earlier.
discussed earlier.
Table 23-6 Active Protocol — Encapsulation and Security Protocol
MODE SECURITY
PROTOCOL
Tunnel ESP
Transport AH
23.5.2 Security Parameter Index (SPI)
An SPI is used to distinguish different SAs terminating at the same destination and using the same IPSec
protocol. This data allows for the multiplexing of SAs to a single gateway. The SPI (Security Parameter
Index) along with a destination IP address uniquely identify a particular Security Association (SA). The SPI
is transmitted from the remote VPN gateway to the local VPN gateway. The local VPN gateway then uses
the network, encryption and key values that the administrator associated with the SPI to establish the tunnel.
protocol. This data allows for the multiplexing of SAs to a single gateway. The SPI (Security Parameter
Index) along with a destination IP address uniquely identify a particular Security Association (SA). The SPI
is transmitted from the remote VPN gateway to the local VPN gateway. The local VPN gateway then uses
the network, encryption and key values that the administrator associated with the SPI to establish the tunnel.
Current ZyXEL implementation assumes identical outgoing and incoming SPIs.
To edit this menu, move the cursor to the Edit Manual Setup field in Menu 27.1.1 – IPSec Setup press
[SPACE BAR] to select Yes and then press [ENTER] to go to Menu 27.1.1.2 – Manual Setup.
[SPACE BAR] to select Yes and then press [ENTER] to go to Menu 27.1.1.2 – Manual Setup.