Banners

Cisco routers have two different types of banners: login and EXEC. Both of these banners should be enabled with a stern warning that all access attempts are logged, and unauthorized attempts to penetrate the system will be prosecuted to the fullest extent of the law. Placing a warning about logging all attempts at access is the equivalent of placing a home security system placard on your front lawn. Even if you do not log access, it might discourage some attempts. The name of the company, the IP address, or any other information that unnecessarily reveals information about your system should not be included on the banner. A sample banner is as follows:

This equipment is privately owned.
All access to this equipment is logged.
Disconnect immediately if you are not an authorized user.
Violators will be prosecuted to the fullest extent of the law.
Contact [email protected]

As with most other security settings, this banner has purposefully avoided giving any information, including using an e-mail address that will disclose no more information than absolutely necessary.