Symptom

In ISE 3.4 command ip domain-name is not accepting certain domain names. For example, top-level domain names longer than 6 characters, such as example.example.example. It returns an error "Not a valid domain name". Trying the same syntax and domain name in the prior version won't throw an error. This can also cause the setup not to complete and stuck right after the I/O bandwidth tests and attempts to sync with the NTP server(s)

Conditions

This can happen during 1) Initial setup 2) Updating the DNS domain via the configuration command ip domain-name

Workaround

For initial setups of ISE 3.4 and either the top-level or second-level domain names are not within the range of 2 to 6 characters, set ISE up with a DNS domain-name within the range, apply ISE 3.4 Patch 1 (or later) and then update the DNS domain-name to the desired value.

Further Problem Description