ZyXEL Communications 792H manual Des, DH1, MD5

Prestige 792H G.SHDSL Router

Table 36-3Menu 27.1.1.1 IKE Setup

FIELD	DESCRIPTION	EXAMPLE
Encryption	When DES is used for data communications, both sender and receiver must	DES
Algorithm	know the same secret key, which can be used to encrypt and decrypt the
	message or to generate and verify a message authentication code. 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.
	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	SHA1
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]. See	ESP
	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].	MD5
Algorithm
SA Life Time	Define the length of time before an IPSec 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.

36-12 VPN/IPSec Setup