ZyXEL Communications P-2602 manual IKE Phases, VPN Screens

P-2602H(W)(L)-DxA Series User’s Guide

Table 87 Edit VPN Policies

LABEL	DESCRIPTION
Encryption	Select DES, 3DES, AES or NULL from the drop-down list box.
Algorithm	When you use one of these encryption algorithms for data communications, both
	the sending device and the receiving device must use the same secret key, which
	can be used to encrypt and decrypt the message or to generate and verify a
	message authentication code. The DES encryption algorithm uses a 56-bit key.
	Triple DES (3DES) is a variation on DES that uses a 168-bit key. As a result,
	3DES is more secure than DES. It also requires more processing power, resulting
	in increased latency and decreased throughput. This implementation of AES uses
	a 128-bit key. AES is faster than 3DES.
	Select NULL to set up a tunnel without encryption. When you select NULL, you
	do not enter an encryption key.
Authentication	Select SHA1 or MD5 from the drop-down list box. MD5 (Message Digest 5) and
Algorithm	SHA1 (Secure Hash Algorithm) are hash algorithms used to authenticate packet
	data. The SHA1 algorithm is generally considered stronger than MD5, but is
	slower. Select MD5 for minimal security and SHA-1for maximum security.
Advanced	Click Advanced to configure more detailed settings of your IKE key management.
Back	Click Back to return to the previous screen.
Apply	Click Apply to save your changes back to the ZyXEL Device.
Cancel	Click Cancel to begin configuring this screen afresh.

17.12 IKE Phases

There are two phases to every IKE (Internet Key Exchange) negotiation – phase 1 (Authentication) and phase 2 (Key Exchange). A phase 1 exchange establishes an IKE SA and the second one uses that SA to negotiate SAs for IPSec.

Figure 125 Two Phases to Set Up the IPSec SA

In phase 1 you must:

•Choose a negotiation mode.

•Authenticate the connection by entering a pre-shared key.

234 Chapter 17 VPN Screens