ISE admin server with 16 character hostname

Question

Our ISE admin servers were inadvertently built with 16 character hostnames. Active directory has a 15 character limit for hostnames. This causes the 16th character to be truncated. The secondary admin server fails to connect to AD because the hostname no longer looks unique. Is there a work around for this other than rebuilding the ISE servers?

Answer 1

Hi Jeff,
you need not rebuild your entire ISE nodes. You have to follow the below steps.
Changing the Hostname or IP Address of a Standalone Cisco ISE Node
You can change the hostname, IP address, or domain name of standalone Cisco ISE nodes. You cannot use “localhost” as the hostname for a node.
Before You Begin
If the Cisco ISE node is part of a distributed deployment, you must remove it from the deployment and ensure that it is a standalone node.
Step 1 Change the hostname or IP address of the Cisco ISE node using the hostname , ip address, or ip domain-name command from the Cisco ISE CLI.
Step 2 Restart the Cisco ISE application configuration using the application stop ise command from the Cisco ISE CLI to restart all the services.
Step 3 Register the Cisco ISE node to the primary Administration node if it part of a distributed deployment.
Note If you are using the hostname while registering the Cisco ISE node, the fully qualified domain name (FQDN) of the standalone node that you are going to register, for example, abc.xyz.com must be DNS-resolvable from the primary Administration node. Otherwise, node registration fails. You must enter the IP addresses and FQDNs of the Cisco ISE nodes that are part of your distributed deployment in the DNS server.
After you register the Cisco ISE node as a secondary node, the primary Administration node replicates the change in the IP address, hostname, or domain name to the other Cisco ISE nodes in your deployment.
Make sure that you also update the DNS record with new hostname and replace the certificate unless you are using wildcard cert.