ZyXEL Communications P-660HN-51 - Pre-Shared Key; Diffie-Hellman (DH) Key Groups

Chapter 13 IPSec
P-660HN-51 User’s Guide
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The type of ID can be a domain name, an IP address or an e-mail address. The content is the IP address,
domain name, or e-mail address.
13.4.7.1 ID Type and Content Examples
Two IPSec routers must have matching ID type and content configuration in order to set up a VPN
tunnel.
The two Zyxel Devices in this example can complete negotiation and establish a VPN tunnel.
The two Zyxel Devices in this example cannot complete their negotiation because Zyxel Device B’s
Local ID type is IP, but Zyxel Device A’s Remote ID type is set to E-mail. An “ID mismatched” message
displays in the IPSEC LOG.
13.4.8 Pre-Shared Key
A pre-shared key identifies a communicating party during a phase 1 IKE negotiation (see Section 13.4.3
on page 159 for more on IKE phases). It is called “pre-shared” because you have to share it with another
party before you can communicate with them over a secure connection.
13.4.9 Diffie-Hellman (DH) Key Groups
Diffie-Hellman (DH) is a public-key cryptography protocol that allows two parties to establish a shared
secret over an unsecured communications channel. Diffie-Hellman is used within IKE SA setup to
establish session keys. 768-bit, 1024-bit 1536-bit, 2048-bit, and 3072-bit Diffie-Hellman groups are
supported. Upon completion of the Diffie-Hellman exchange, the two peers have a shared secret, but
the IKE SA is not authenticated. For authentication, use pre-shared keys.
Table 60 Local ID Type and Content Fields
LOCAL ID TYPE= CONTENT=
IP Type the IP address of your computer.
DNS Type a domain name (up to 31 characters) by which to identify this Zyxel Device.
E-mail Type an e-mail address (up to 31 characters) by which to identify this Zyxel Device.
The domain name or e-mail address that you use in the Local ID Content field is used
for identification purposes only and does not need to be a real domain name or e-
mail address.
Table 61 Matching ID Type and Content Configuration Example
ZYXEL DEVICE A ZYXEL DEVICE B
Local ID type: E-mail Local ID type: IP
Local ID content: tom@yourcompany.com Local ID content: 1.1.1.2
Remote ID type: IP Remote ID type: E-mail
Remote ID content: 1.1.1.2 Remote ID content: tom@yourcompany.com
Table 62 Mismatching ID Type and Content Configuration Example
ZYXEL DEVICE A ZYXEL DEVICE B
Local ID type: IP Local ID type: IP
Local ID content: 1.1.1.10 Local ID content: 1.1.1.2
Remote ID type: E-mail Remote ID type: IP
Remote ID content: aa@yahoo.com Remote ID content: 1.1.1.0