The backup may fail with error 58 its because of the below following reasons
Netbackup client services are not running
The Firewall or anti virus enabled
Please turn of and check else try to add the bpcd, vnetd, and pbx port to firewall exceptiton rules. and check.
if that does not work..
please proceed with the below troubleshooting steps
From Master :-
--> ping <client name>
--> nslookup <client name>
--> grep <client name> /etc/hosts
--> bpcltncmd -hn <client name>
--> bpcltncmd -ip <client IP>
--> bpcltncmd -self
--> bpclntcmd -pn
-->bpcntcmd -hn <client name>
-->bpcltncmd -ip <client IP>
Hope from this we will be able to figure out what was the exact issue.