Nortel BSR222, Configuration, Page: 243 / 451

Chapter 13 VPN 243
Nortel Business Secure Router 222 Configuration — Basics
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 1 024-bit (1Kb) random
number.
DH5 refers to Diffie-Hellman Group 5, a 1 536-bit random number.
Phase 2 A phase 2 exchange uses the IKE SA established in phase 1 to
negotiate the SA for IPSec.
Multiple Proposal Select this check box to allow the Business Secure Router to use any
of its phase 2 encryption and authentication algorithms when
negotiating an IPSec SA.
Clear this check box to have the Business Secure Router use only the
phase 2 encryption and authentication algorithms when negotiating an
IPSec SA.
Active Protocol Select ESP or AH from the drop-down list. The Business Secure
Router's IPSec Protocol must be identical to the remote VPN switch.
The ESP (Encapsulation Security Payload) protocol (RFC 2406)
provides encryption as well as the authentication offered by AH. If you
select
ESP here, you must select options from the Encryption
Algorithm and Authentication Algorithm fields. The AH protocol
(Authentication Header Protocol) (RFC 2402) was designed for
integrity, authentication, sequence integrity (replay resistance), and
nonrepudiation, but not for confidentiality, for which the ESP was
designed. If you select
AH here, you must select options from the
Authentication Algorithm field.
Encryption
Algorithm Select DES , 3DES , AES or NULL from the drop-down list.
When you use one of these encryption algorithms for data
communications, both the sending device and the receiving device
must use the same secret key, which can be used to encrypt and
decrypt the message or to generate and verify a message
authentication code. The 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 increased latency and decreased
throughput. You can select a 128-bit, 192-bit, or 256-bit key with this
implementation of
AES . AES is faster than 3DES .
Select NULL to set up a tunnel without encryption. When you select
NULL , you do not enter an encryption key.
Authentication
Algorithm Select SHA1 or MD5 from the drop-down list. MD5 (Message Digest
5) and SHA1 (Secure Hash Algorithm) are hash algorithms used to
authenticate packet data. The SHA1 algorithm is generally considered
stronger than MD5, but is slower. Select MD5 for minimal security and
SHA-1 for maximum security.
Table 59 VPN Branch Office Advanced Rule Setup
Label Description