Prestige 652 ADSL Security Router

Table 25-5Menu 27.1.1.1 — IKE Setup

FIELD

DESCRIPTION

EXAMPLE

 

Press [SPACE BAR] to choose from 3DES or DES and then press [ENTER].

 

 

 

 

Authentication

MD5 (Message Digest 5) and SHA1 (Secure Hash Algorithm) are hash

MD5

Algorithm

algorithms used to authenticate packet data. The SHA1 algorithm is

 

 

generally considered stronger 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

28800

(Seconds)

renegotiates in this field. It may range from 60 to 3,000,000 seconds (almost

(default)

 

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

DH1

 

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].

ESP

 

See earlier for a discussion of these protocols.

 

 

 

 

Encryption

Press [SPACE BAR] to choose from NULL, 3DES or DES and then press

DES

Algorithm

[ENTER]. Select NULL to set up a tunnel without encryption.

 

Authentication

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

SHA1

Algorithm

 

 

SA Life Time

Define the length of time before an IKE Security Association automatically

28800

(Seconds)

renegotiates in this field. It may range from 60 to 3,000,000 seconds (almost

(default)

 

35 days).

 

Encapsulation

Press [SPACE BAR] to choose from Tunnel mode or Transport mode and

Tunnel

 

then press [ENTER]. See earlier for a discussion of these.

 

 

 

 

Perfect Forward

Perfect Forward Secrecy (PFS) is disabled (None) by default in phase 2

None

Secrecy (PFS)

IPSec SA 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.

25-16

VPN/IPSec Setup