Command Reference Guide

3Com Router 5000 Family and Router 6000 Family esp authentication-algorithm ● 131
Command Reference
esp authentication-algorithm
Purpose Use the esp authentication-algorithm command to set the authentication
algorithm used by ESP.
Use the undo esp authentication-algorithm command to set ESP not to
authenticate packets.
Syntax esp authentication-algorithm { md5 | sha1 }
undo esp authentication-algorithm
Parameters md5
Use MD5 algorithm with the length of the key 128
bits.
sha1
Use SHA1 algorithm with the length of the key 160
bits.
Default By default, MD5 algorithm is used.
Example Set a proposal that adopts ESP, and uses SHA1.
[3Com] ipsec proposal prop1
[3Com-ipsec-proposal- prop1] transform esp
[3Com-ipsec-proposal- prop1] esp authentication-algorithm sha1
View This command can be used in the following views:
■ IPSec Proposal view
Description MD5 is faster than SHA1, while SHA1 is securer than MD5.
ESP permits a packet to be encrypted or authenticated or both.
The encryption and authentication algorithm used by ESP cannot be set to vacant at
the same time.
The undo esp authentication-algorithm command is not used to restore
the authentication algorithm to the default; instead it is used to set the
authentication algorithm to vacant, i.e. not authentication. When the encryption
algorithm is not vacant, the
undo esp authentication-algorithm
command is valid.
The proposal used by the ipsec policies set at both ends of the security tunnel must be
set as having the same authentication algorithm.