DNS servers that are added after initial configuration are not present in the /etc/resolv.conf file

During initial configuration, only one DNS server can be added. If you add multiple DNS servers using the Appliance GUI after initial configuration, the newly added DNS servers are not synced with the /etc/resolv.conf file present in the NetBackup primary container . The /etc/resolv.conf file has only one DNS entry done during initial configuration. (IA-31849)

Workaround:

There is no workaround for this issue