3Com Switch 8800 Advanced Software V5 Configuration Guide

974 CHAPTER 74: PASSWORD CONTROL CONFIGURATION
4 Password history
With this feature enabled, the system maintains certain entries of passwords that a
user has used. When a user changes the password, the system checks the new
password against the used ones to see whether it was used before and, if so,
displays an error message.
You can set the maximum number of history password records for the system to
maintain for each user. When the number of history password records exceeds
your setting, the latest record will overwrite the earliest one.
5 Login attempt restriction
Limiting the times of entering wrong passwords can effectively prevent malicious
password cracking.
Once a user fails to pass authentication, the system adds the user into a blacklist.
When a user tries but fails to login for the allowed maximum number of successive
authentication attempts, the system may prohibit or allow the user to login,
depending on your choice:
■ Prohibiting the user from logging into the system until the user is removed
from the blacklist.
■ Allowing the user to log in and removing the user from the blacklist when the
user logs into the system or the blacklist entry times out (the blacklist entry
aging time is 20 minutes).
■ Prohibiting the user from logging in for a configurable period of time. After this
period, the user will be deleted from the blacklist and can log into the system
again.
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■ A blacklist can contain up to 1,024 entries. A login attempt using a wrong
username will undoubtedly fail but the username is not added into the
blacklist.
■ FTP users and virtual terminal line (VTY) users are blacklisted when they fail the
authentication.
■ Users accessing the system through the Console or AUX interface are never
blacklisted. This is because the system is unable to obtain the IP addresses of
these users and these users are privileged and therefore relatively secure to the
system.
6 Password composition
A password can be a combination of characters from the following four
categories:
■ Uppercase letters A to Z
■ Lowercase letters a to z
■ Digits 0 to 9
■ 32 special characters including blank space and
~‘!@#$%^&*()_+-={}|[]:";’<>,./.