Prestige 2602H/HW Series User’s Guide

Figure 264 Menu 27.1.1.1KE Setup

Menu 27.1.1.1 - IKE Setup

Phase 1

Negotiation Mode= Main

PSK=

Encryption Algorithm = AES

Authentication Algorithm = SHA1

SA Life Time (Seconds)= 28800

Key Group= DH1

Phase 2

Active Protocol = ESP

Encryption Algorithm = AES

Authentication Algorithm = MD5

SA Life Time (Seconds)= 28800

Encapsulation = Tunnel

Perfect Forward Secrecy (PFS)= None

Press ENTER to Confirm or ESC to Cancel:

The following table describes the fields in this menu.

Table 149 Menu 27.1.1.1 IKE Setup

FIELD

DESCRIPTION

 

 

Phase 1

 

 

 

Negotiation

Press [SPACE BAR] to choose from Main or Aggressive and then press [ENTER].

Mode

See earlier for a discussion of these modes. Multiple SAs connecting through a

 

secure gateway must have the same negotiation mode.

PSK

Prestige gateways authenticate an IKE VPN session by matching pre-shared keys.

 

Pre-shared keys are best for small networks with fewer than ten nodes. Enter your

 

pre-shared key here. Enter up to 31 characters. Any character may be used, including

 

spaces, but trailing spaces are truncated.

 

Both ends of the VPN tunnel must use the same pre-shared key. You will receive a

 

“PYLD_MALFORMED” (payload malformed) packet if the same pre-shared key is not

 

used on both ends.

Encryption

The Prestige and the remote IPSec router generate an encryption key from the Diffie-

Algorithm

Hellman key exchange. Prestige 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 slightly

 

increased latency and decreased throughput.

 

This implementation of AES uses a 128-bit key. AES is faster than 3DES.

 

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

 

 

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

 

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

(Seconds)

renegotiates 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.

Chapter 43 VPN/IPSec Setup

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