ISE 2.x || Is the ISE hostname limits 15 or 19 characters?

[musultan]

Hi,

I came across the release notes from all ISE version 1.x, 2.x and got to know the following...

https://www.cisco.com/c/en/us/td/docs/security/ise/2-3/release_notes/ise23_rn.html

Hostname

Must not exceed 19 characters. Valid characters include alphanumerical characters (A–Z, a–z, 0–9) and the hyphen (-). The first character must be a letter.

Per my knowledge, the limit was 15 characters for ISE host-name.

I also came across the same discussion and they mentioned the 15 characters.

Please confirm that if the limitation is changed now from 15 to 19 characters or it is a typo error and doc bug need to be filed to correct it?

[Arne Bier]

In ISE 2.4 it's still 19

ise01/admin(config)# hostname ?
  <WORD>  New hostname string (Max Size - 19)

Below is an example of 19 character hostname (valid)

ise01/admin(config)# hostname a23456789abcdefghij
% Warning: Hostname change disallowed as this node is part of a deployment. Make it a standalone to change the hostname.
% unable to change hostname to a23456789abcdefghij

And a 20 character hostname is invalid syntax
ise01/admin(config)# hostname a23456789abcdefghijk
                                      ^
% param string too long detected at '^' marker.

[musultan]

Thanks Arne....

So, the limitation of hostname length for ISE is 19.
However, if the ISE needs to be joined to AD the limitation is 15 characters.
ISE must show it as warning in CLI during setup.
i can see the following bug but looks like it is still not taken care.

Ref Bug: https://bst.cloudapps.cisco.com/bugsearch/bug/CSCuo12855

any comments will be appreciated....