Internet Security Appliance User's Guide

Chapter 19 IPSec VPN
ZyWALL 5/35/70 Series User’s Guide
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The ZyWALL 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.
" The ZyWALL’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 ZyWALL and the remote
IPSec router authenticate each other successfully.
In the following example, the ID type and content do not match so the authentication fails and
the ZyWALL and the remote IPSec router cannot establish an IKE SA.
It is also possible to configure the ZyWALL to ignore the identity of the remote IPSec router.
In this case, you usually set the peer ID type to Any. This is not as secure as other peer ID
types, however.
Certificates
It is also possible for the ZyWALL and remote IPSec router to authenticate each other with
certificates. In this case, the authentication process is different.
• Instead of using the pre-shared key, the ZyWALL and remote IPSec router check each
other’s certificates.
• The local ID type and ID content come from the certificate. On the ZyWALL, you simply
select which certificate to use.
• If you set the peer ID type to Any, the ZyWALL authenticates the remote IPSec router
using the trusted certificates and trusted CAs you have set up. Alternatively, if you want to
use a specific certificate to authenticate the remote IPSec router, you can use the
information in the certificate to specify the peer ID type and ID content.
Table 111 VPN Example: Matching ID Type and Content
ZYWALL REMOTE IPSEC ROUTER
Local ID type: E-mail Local ID type: IP
Local ID content: [e-mail] 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: [e-mail]
Table 112 VPN Example: Mismatching ID Type and Content
ZYWALL REMOTE IPSEC ROUTER
Local ID type: E-mail Local ID type: IP
Local ID content: [e-mail] Local ID content: 1.1.1.2
Peer ID type: IP Peer ID type: E-mail
Peer ID content: 1.1.1.15 Peer ID content: [e-mail]