Password-Length Enforcement
You can globally set a minimum length for all router passwords with the
security passwords min-length length command.
Password Encryption
Many types of passwords are stored in clear text in the configuration, by
default. To prevent casual discovery of these passwords, use the service
password-encryption command. Software to decrypt passwords that are
ciphered with this command is widely available on the Internet, so it should
not be relied on to protect highly sensitive passwords.
Enhanced Username Password Security
When configuring a local username/password database on a router, use the
username username secret password command. This protects the password
with a MD5 hash rather than plain text or weak Type 7 encryption.
Password Example
Example 5-1 shows a configuration that incorporates all the password
features previously discussed.
Example 5-1 Configuring Router Passwords
service password-encryption
security passwords min-length 6
enable secret 5 $1$jSlS$QbQmCuRx0UfOgQiMkxbHk0
enable password 7 053B0A2F70427A5A0111
username admin secret 5 $1$zltV$9tNP0xX4ehfQ0pKceNG6A/
line con 0
password 7 053B0A2F70427A5A0111
login
stopbits 1
line aux 0
password 7 01230A240A05325C3958
login
stopbits 1
line vty 0 4
password 7 046B07265E2F781D110D
login