Known Issue - bptestbpcd returns "failed: 7647" when attempting to talk to a media server

Problem: 

In NetBackup 8.1, upon running bptestbpcd from a Master Server to a Media Server, the on-screen response ends with the following (or similar):

Example on-screen output:
bptestbpcd -client My-Media-Server -verbose
<16> bptestbpcd main: Function ConnectToBPCD(My-Media-Server) failed: 7647
<16> bptestbpcd main: Proxy peer does not conform to proxy protocol
<2> bptestbpcd: Proxy peer does not conform to proxy protocol
<2> bptestbpcd: EXIT status = 7647

Cause: 

The above has been observed when the NetBackup Client Service on the problem host, has been changed to start with an account other than LocalSystem (which is the default).

Solution: 

It is recommended to change the Log On associated with the NetBackup Client Service back to LocalSystem - an account which has the needed permissions.

Once the NetBackup Client Service account has been changed and restarted, communication with the host is successful.