NetBackup 7.0.1 and above attempts to use the PBX port for connections before falling back to vnetd, daemon, and legacy ports.
http://seer.entsupport.symantec.com/docs/357820.htm
Overview:
After applying the NB_7.0.1 release update, the default destination port changes for most legacy connections. The initial attempt to connect is made to the PBX port. If a firewall or other issue prevents the connection, it reverts to the legacy connect option selection, which makes it reverse compatible with NetBackup versions 7.0, 6.5, and 6.0.
Note: The NB_7.0.1 release update also contains a new version of PBX.
Troubleshooting:
The
bptestbpcd command (servers) and
bptestnetconn (servers and clients) and NetBackup debug logs show when port 1556 is used in place of 13724 or other daemon ports. For example:
# admincmd/bptestbpcd
1 1 1
10.80.74.69:51164 -> 10.80.74.69:1556
10.80.74.69:51165 -> 10.80.74.69:1556
If a firewall does not permit connections to
vnetd and daemon ports, the PBX port must be used. You should then enable logging for PBX (product id 50936) OID 103 and NetBackup (product id 51216) OID 137.