Register ACS 5.4 Secondary to Primary problem after change hostname

[TIAGO MATIAS]

After i change the hostname from my ACS Secondary i can´t register to primary again.

The erros is :

This System Failure occurred:  ACS50RMIAPI Unable to register node. Possible cause of this exception is an invalid hostname or invalid ip address has been entered.. Your changes have not been saved.Click OK to return to the list page. 

I need reimage the box ?

[Flavio Miranda]

 Hi Tiago,

  Is it the new hostname resolvable by the DNS ? 

[TIAGO MATIAS]

Hi Flami, i will check it, this was a old hostname that we need use again.

The resolvable DNS  is mandatory?  i try register using the IP.

Thanks a Lot.

[Flavio Miranda]

Well, read that out from a Cisco Documentation:

" Prerequisites:
• The fully qualified domain name (FQDN) of the standalone node that you are going to register, for
example, ise1.cisco.com must be Domain Name System (DNS)-resolvable from the primary
Administration ISE node. Otherwise, node registration will fail. You must enter the IP addresses and
FQDNs of the ISE nodes that are part of your distributed deployment in the DNS server."

[TIAGO MATIAS]

OK, on ISE the DNS is mandatory in my case is a ACS 1121 appliance.

I believe that is other problem.

Thanks.

[TIAGO MATIAS]

After reboot the PRIMARY instance i register the Secodary with sucess.

Thanks a Lot.

[kimseyj]

In building up two new ACS 5.5 servers and trying to get the secondary to register to the primary I received the exact same error message as above.   I can confirm that in my situation, both servers DNS names were fully resolvable.

The solution for me was also the rebooting of both servers (though perhaps only one of them was needed, I reloaded them both from the CLI).  After the reboot the secondary seamlessly registered with the primary.

[dan]

worked for me as well but need to reboot both appliances.

[jewfcb001]

I found the same issue . I try to reboot primary and new secondary instance . it can fixed the issue . 

Thank you.