ConfD User Community

Is there any built command to change the banner for CLI


#1

In the confd.conf, the banner is default set to “Welcome to CLI”.
Is there any built in command to change this banner setting?

For CLI, I can see these settings can be changed:
config-mode-prompt
operational-mode-promp
session-timeout
show-default
telnet

But I did not see how to enable one command to let the user to edit the banner?


#2

As banner is part of dynconfig, it can be changed during runtime when dynconfig is used. Seeconfd.conf/confdConfig/runtimeReconfiguration` in the ConfD User Guide.

Then you can configure it directly (set confdConfig cli banner "my banner" + commit) or create e.g. clispec custom command, that changes dynconfig value.

Similar example how to change prompt is in confdconf/dyncfg example directory.


#3

What is the limit of the string length for banner can be configured?


#4

If you make the effort to peek into src/confd/dyncfg/confd_dyncfg.yang you will notice that the banner is of YANG string built-in type. If you then check out YANG 1.1 RFC 7950 you can find the answer to your question under https://tools.ietf.org/html/rfc7950#section-9.4.4.

What string length did you have in mind for the banner? Something larger than a string length of 18446744073709551615?


#5

Can we restrict this length size ? When I try to limit using data-model with tailf:link…It was not working. W
As of now my system is taking such big string but eventually crashing.

Whenever the length is increasing more than 256k lenght it is throwing “Bad Packet lenght”.

output:
Bad packet length 262156.
Disconnecting: Packet corrupt


#6

Using tailf:link to restrict the length of a string seems a bit odd, normally you would use the YANG lenght statement.


#7

Where do i put the bannerFile to read the banner from a file?


#8

Add it to CLI section of confd.conf, You can use relative or absolute file path

 <cli>
    <bannerFile>./banner.txt</bannerFile>
    <!--<bannerFile>/tmp/banner.txt</bannerFile>-->
  </cli>

#9

Is there any other way possible to upload this file (eg. via SCP)?

We have an access switch with Confd integrated to it and normally confd.conf is not available for editing for our customers. If the customers want to have a custom login banner (via a file), what options do they have apart from specifying it via confd.conf file?