3Com 3C13636 Configuration Manual page 1117

3Com Router 3000 Ethernet Family
Configuration Guide
Table 7-5 Select security algorithm
Configure encryption algorithm used by
ESP
Configure undo packet encrypting for ESP
Configure authentication method used by
ESP
Configure undo packet authentication for
ESP
Configure authentication method used by
AH protocol
Restore AH protocol default authentication
method
ESP will allow encryption and authentication process for packet at the same time, or
encryption
authentication-algorithm command will not restore authentication method to the
default, but configure authentication method as null, i.e., undo authentication-method.
When encryption algorithm is null, undo esp authentication-algorithm command is
invalid. AH protocol has no encrypting function and can only perform authentication for
packets. undo ah authentication-algorithm command is used to restore AH protocol
default authentication method as md5. On both ends of security tunnel, the IPSec
proposals referenced by IPSec policy must be configured with the same authentication
method and encryption algorithm.
ESP protocol supports three types of encryption algorithms: des, 3des and aes, and
two authentication algorithms: hmac-md5 and hmac-sha1.
AH protocol supports two types of authentication algorithms: hmac-md5 and
hmac-sha1.
By default, encryption algorithm used by ESP is des and authentication method used is
md5. Authentication method used by AH protocol is md5.
Note:
Only when the desired security protocol is selected with the transform command, can
security algorithm be configured. For example, if you can select ESP, you can only
configure those security algorithms particular to ESP, excluding those for AH.
Operation
only or process
3Com Corporation
7-13
Chapter 7 IPSec Configuration
esp encryption-algorithm { 3des |
des | aes [ 128 | 192 | 256 ] }
undo esp encryption-algorithm
esp authentication-algorithm
{ md5 | sha1 }
undo esp authentication-algorithm
ah authentication-algorithm { md5
| sha1 }
undo ah authentication-algorithm
authentication only.
Command
Attention, undo esp