ZyXEL Communications wireless n gigbit router zyxel manual 212

Chapter 15 IPSec VPN

Table 69 Security > VPN > General > Rule Setup: IKE (Advanced) (continued)

LABEL	DESCRIPTION
Pre-Shared Key	Type your pre-shared key in this field. A pre-shared key identifies a
	communicating party during a phase 1 IKE negotiation. It is called
	"pre-shared" because you have to share it with another party before
	you can communicate with them over a secure connection.
	Type from 8 to 31 case-sensitive ASCII characters or from 16 to 62
	hexadecimal ("0-9", "A-F") characters. You must precede a
	hexadecimal key with a "0x” (zero x), which is not counted as part of
	the 16 to 62 character range for the key. For example, in
	"0x0123456789ABCDEF", “0x” denotes that the key is hexadecimal
	and “0123456789ABCDEF” is the key itself.
	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.
IKE Phase 2
Encapsulation	Select Tunnel mode or Transport mode.
Mode
IPSec Protocol	Select the security protocols used for an SA.
	Both AH and ESP increase processing requirements and
	communications latency (delay).
	If you select ESP here, you must select options from the Encryption
	Algorithm and Authentication Algorithm fields (described below).
Encryption	Select which key size and encryption algorithm to use in the IKE SA.
Algorithm	Choices are:
	DES - a 56-bit key with the DES encryption algorithm
	3DES - a 168-bit key with the DES encryption algorithm
	The NBG-460N and the remote IPSec router must use the same
	algorithms and keys. Longer keys require more processing power,
	resulting in increased latency and decreased throughput.
Authentication	Select which hash algorithm to use to authenticate packet data in the
Algorithm	IPSec SA. Choices are SHA1 and MD5. SHA1 is generally considered
	stronger than MD5, but it is also slower.
SA Life Time	Define the length of time before an IPSec SA automatically
	renegotiates in this field. The minimum value is 180 seconds.
	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.

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NBG-460N User’s Guide