Prestige 334 User’s Guide

Table 106 Menu 27.1.1.1 IKE Setup

FIELD DESCRIPTION

Authentication MD5 (Message Digest 5) and SHA1 (Secure Hash Algorithm) are hash algorithms Algorithm used to authenticate packet data. The SHA1 algorithm is generally considered stron-

ger than MD5, but is slightly slower.

Press [SPACE BAR] to choose from SHA1 or MD5 and then press [ENTER].

SA Life Time Define the length of time before an IKE Security Association automatically renegoti- (Seconds) ates in this field. It may range from 60 to 3,000,000 seconds (almost 35 days).

A short SA Life Time increases security by forcing the two VPN gateways to update the encryption and authentication keys. However, every time the VPN tunnel renegotiates, all users accessing remote resources are temporarily disconnected.

Key Group You must choose a key group for phase 1 IKE setup. DH1 (default) refers to Diffie- Hellman Group 1 a 768 bit random number. DH2 refers to Diffie-Hellman Group 2 a 1024 bit (1Kb) random number.

Phase 2

Active Protocol Press [SPACE BAR] to choose from ESP or AH and then press [ENTER]. See earlier for a discussion of these protocols.

Encryption Press [SPACE BAR] to choose from NULL, 3DES or DES and then press [ENTER]. Algorithm Select NULL to set up a tunnel without encryption.

Authentication Press [SPACE BAR] to choose from SHA1 or MD5 and then press [ENTER]. Algorithm

SA Life Time Define the length of time before an IPSec Security Association automatically (Seconds) renegotiates in this field. It may range from 60 to 3,000,000 seconds (almost 35

days).

Encapsulation Press [SPACE BAR] to choose from Tunnel mode or Transport mode and then press [ENTER]. See earlier for a discussion of these.

Perfect Forward Perfect Forward Secrecy (PFS) is disabled (None) by default in phase 2 IPSec SA Secrecy (PFS) setup. This allows faster IPSec setup, but is not so secure. Press [SPACE BAR] and choose from DH1 or DH2 to enable PFS. DH1 refers to Diffie-Hellman Group 1 a 768

bit random number. DH2 refers to Diffie-Hellman Group 2 a 1024 bit (1Kb) random number (more secure, yet slower).

When you have completed this menu, press [ENTER] at the prompt “Press ENTER to Confirm…” to save your configuration, or press [ESC] at any time to cancel.

34.4 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.

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Chapter 34 VPN/IPSec Setup