I had upgraded netbackup appliance 5220 from version 22.214.171.124 to 2.7.2, then I found netbackup java console 7.7.2 can not connect to nbu5220(master server).
CertificateAuthenticationException encountered, NetBackup could not initiate a trust relationship with host "xxx". Ensure that your Domain Name Service (DNS) resolves the hostname to the correct IP address and check network connectivity.
ping from my notebook to nbu5220:ok
ping from my nbu5220 to notebook:ok
Please have a look at the attachment in this post:
The instructions in the txt file is for a Windows server.
If you are not comfortable translating Windows to Linux paths, please log a call with Veritas Support for Linux instructions.