Banner

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Introduction

Creating a banner can be very useful if you need to manage a lot of devices that look all the same. When you connect to the device (either on a web page, application or terminal session) you can quickly see where you are connecting.

Appart from the address, this is a standard CUCM logon screen, exactly the same like in all CUCM servers

Security considerations

Most of the time banners can be used to show information regarding privileged access and eventual penalties. These announcements are usually innocuous. An announcement can also identify the machine and give unauthorized persons additional information on what the machine is or does.

Keep your announcements simple - CUCM announcements are shown at the WEB login window, i.e., before the user logs in. Unauthorized users can see this announcement!

What information then?

This depends on your business needs and rules mostly. Usually it's enough to identify the machines or clusters with their code name or their function, like:

  • Pre-prod[uction]
  • Lab
  • Europe
  • US

Other times, the host name could be just enough:

  • srv1231av
  • ucsrv01pub

Anyway, remember to make your information consistent across your environment and most of all not ambiguous.

Simple banner

A banner shows the user additional information on the machine the user is connecting.

The banner function is per server and not per cluster. If you change the banner of the Publisher server, only that server will show that banner.

Let's create an ASCII text file with the following content:

Simple banner server - Cluster ALDERAN

Access to this server by unauthorized persons is strictly forbidden.

Save this into a text file like banner.txt (or any other name of your liking).

In the OS menu, select "Software Upgrades" and then "Customized Logon Message", select and upload the test file.

Only CUCM supports the banner function completely. UCCX only shows the banner on the OS Admin and text console. CUCX does not allow to upload the file

Returning to the main menu, now the message is visible:

Banner-simple.png

The message however is not very visible.

ASCII banner

As the banner file can only be a text file, using an image is out of the question. We can however use ASCII art to draw a bigger banner that can be better seen.

The challenge to draw ASCII banners is that they work well with fixed width fonts like on terminal consoles. CUCM however does not use this kind font. Instead it uses Verdana.

The challenge is is that not many characters in Verdana have the same width. In fact, of those who have the same width and can produce something visually appealing are the following:

0 1 2 3 4 5 6 7 8 9 _

So, if we're going to use some ASCII art, we need to use only with these 11 characters.

ASCII banner generator

Any ASCII generator should do. The type of font to use should however be a fixed character font, i.e., the characters should be drawn with only one kind of character.

Here http://www.network-science.de/ascii/ you can find a good generator. The fonts of the "Banner" family are the better ones to draw ASCII banners.

Font: banner

###### #    #   ##   #    # #####  #      ###### 
#       #  #   #  #  ##  ## #    # #      #      
#####    ##   #    # # ## # #    # #      #####  
#        ##   ###### #    # #####  #      #      
#       #  #  #    # #    # #      #      #      
###### #    # #    # #    # #      ###### ###### 

Font: banner3

######## ##     ##    ###    ##     ## ########  ##       ######## 
##        ##   ##    ## ##   ###   ### ##     ## ##       ##       
##         ## ##    ##   ##  #### #### ##     ## ##       ##       
######      ###    ##     ## ## ### ## ########  ##       ######   
##         ## ##   ######### ##     ## ##        ##       ##       
##        ##   ##  ##     ## ##     ## ##        ##       ##       
######## ##     ## ##     ## ##     ## ##        ######## ########

If used directly, without change, they will look like this in CUCM:

Banner-bad.png

This happens because the space and the # characters have different widths on a variable width font like Verdana. The best solution is to replace any space with an _ (underscore), and the # with a digit. The digit 8 is the best as it is the most visible of all the digits.

The result should look like:

88888888_88_____88____888____88_____88_88888888__88_______88888888_
88________88___88____88_88___888___888_88_____88_88_______88_______
88_________88_88____88___88__8888_8888_88_____88_88_______88_______
888888______888____88_____88_88_888_88_88888888__88_______888888___
88_________88_88___888888888_88_____88_88________88_______88_______
88________88___88__88_____88_88_____88_88________88_______88_______
88888888_88_____88_88_____88_88_____88_88________88888888_88888888_
Please introduce an empty line after the last line. It's necessary for proper console display of the banner

In CUCM it will now look like this:

Banner-good.png

And when you login in the console, after you enter the password:

Banner-console.png