ZyXEL Communications NBG420N - Manual (Page 186)

Chapter 15 IPSec VPN
NBG420N User’s Guide
186
Authentication
Before the NBG420N and remote IPSec router establish an IKE SA, they have to verify each
other’s identity. This process is based on pre-shared keys and router identities.
In main mode, the NBG420N and remote IPSec router authenticate each other in steps 5 and 6,
as illustrated below. Their identities are encrypted using the encryption algorithm and
encryption key the NBG420N and remote IPSec router selected in previous steps.
Figure 113 IKE SA: Main Negotiation Mode, Steps 5 - 6: Authentication
The NBG420N and remote IPSec router use a pre-shared key in the authentication process,
though it is not actually transmitted or exchanged.
Note: The NBG420N and the remote IPSec router must use the same pre-shared
key.
Router identity consists of ID type and ID content. The ID type can be IP address, domain
name, or e-mail address, and the ID content is a specific IP address, domain name, or e-mail
address. The ID content is only used for identification; the IP address, domain name, or e-mail
address that you enter does not have to actually exist.
The NBG420N and the remote IPSec router each has its own identity, so each one must store
two sets of information, one for itself and one for the other router. Local ID type and ID
content refers to the ID type and ID content that applies to the router itself, and peer ID type
and ID content refers to the ID type and ID content that applies to the other router in the IKE
SA.
Note: The NBG420N’s local and peer ID type and ID content must match the remote
IPSec router’s peer and local ID type and ID content, respectively.
In the following example, the ID type and content match so the NBG420N and the remote
IPSec router authenticate each other successfully.
Table 67 VPN Example: Matching ID Type and Content
NBG420N REMOTE IPSEC ROUTER
Local ID type: E-mail Local ID type: IP
Local ID content: [email protected] Local ID content: 1.1.1.2
Peer ID type: IP Peer ID type: E-mail
Peer ID content: 1.1.1.2 Peer ID content: [email protected]
5
6