System Banners

A router maintains a number of standard messages for communicating with users. These messages are typically associated with the process of logging into the router. For example, a user is typically shown a "message of the day," followed by a login banner, followed by the login prompt itself. After a successful login, the user is usually shown an "exec banner "; in the special case of a reverse telnet connection (see Chapter 4), the user is shown the "incoming banner" rather than the exec banner. In other words, for a typical console session, you would see:

This is the message of the day banner. (motd banner)
This is the login banner. (login banner)
User access verification

Password: (not echoed)
This is the exec banner. (exec banner)
Router> (user mode prompt)

Each banner configuration statement has the same format: banner-type # message #. The pound character (#) represents the delimiting character of your choice and marks the beginning and end of your message. You cannot use the delimiting character inside the message body. For example, this command sets the message of the day:

Router(config)#banner motd # Router will be rebooted today for
maintenance. #

Messages can contain blank lines and line breaks, as in the following example:

Router(config)#banner motd $
Enter TEXT message. End with the character '$'.

Router will be down until tomorrow.

I guess we should have planned it better.
$
Router(config)#

 

3.9.1. Creating Banners

To create a banner of any type, use the banner command followed by the type of banner and the message:

Router(config)#banner motd #  message  # 
Router(config)#banner login #  message  # 
Router(config)#banner exec #  message  # 
Router(config)#banner incoming #  message  # 

 

3.9.2. Disabling Banners

Normally, once banners are defined, they are displayed. You can't disable a banner; you must delete it with the no form of the banner command:

Router(config)#no banner incoming

Unlike the other banners, the exec and message-of-the-day banners can be disabled on individual lines by using the no exec-banner and no motd-banner commands:

Router(config)#line 5
Router(config-line)#no exec-banner
Router(config-line)#no motd-banner

An unusual side effect is that disabling the exec banner also disables the message-of-the-day banner; disabling the message-of-the-day banner has no effect on the exec banner. To re-enable either of these banners, give the exec-banner or motd-banner command.