NetWorker: NMC cannot connect to NetWorker server, 'Unable to connect to server, Remote system error - Resource temporarily unavailable'

• The NetWorker Management Console (NMC) cannot connect to both NetWorker servers. When connection to the NMC, an error appears stating: 

• The following errors are logged in the NetWorker server's /nsr/logs/daemon.raw:
  • NetWorker: How to use nsr_render_log to render .raw log files

173680 07/08/2019 09:08:37 PM  nsrexecd RPC error RPC client handle: No route to host.
172089 07/08/2019 09:08:37 PM  nsrexecd RPC error Unable to create the connection with '' to host (NetWorker server)  with address (ip-address of NetWorker server) at port number 0.
173678 07/08/2019 09:08:37 PM  nsrexecd RPC critical Check whether the firewall is blocking the client ports on the host (ip-address of NetWorker server).

• Name resolution, ping, and traceroute work fine.
  • NetWorker: Name Resolution Troubleshooting Best Practices

• nsrports connection to the NetWorker server client port times out or is rejected:

• NetWorker services are running on the NetWorker server:
  • Linux: ps -ef | grep nsr
  • Windows: tasklist | findstr nsr

• The nsrrpcinfo command on the NetWorker server shows which ports the server processes are using: 

nve:~ # nsrrpcinfo -p localhost
PROGRAM VERSION PROTOCOL PORT SERVICE
100000  2       tcp      7938 nsrportmapper  Port Mapper
100000  2       udp      7938 nsrportmapper  Port Mapper
390436  1       tcp      9160 nsrexecd       GSS Authentication
390435  1       tcp      9530 nsrexecd       Resource Mirror
390113  1       tcp      7937 nsrexecd       Remote Execution
390440  1       tcp      9327 nsrexecd_nsrfa Remote File Access
390408  1       tcp      9891 nsrpsd         Snapshot Management
390409  1       tcp      8955 nsrsnapckd     Snapshot Management
390402  1       tcp      9001 gstd           GST
390460  1       tcp      7999 auth_proxyd    Authentication Proxy
390103  2       tcp      9858 nsrd           Server
390109  2       tcp      9858 nsrd           Remote Monitoring
390110  1       tcp      9858 nsrd           Jukebox Management
390120  1       tcp      9858 nsrd           License Manager
390105  5       tcp      8385 nsrindexd      Index Database
390105  6       tcp      8385 nsrindexd      Index Database
390107  5       tcp      8197 nsrmmdbd       Media Database
390107  6       tcp      8197 nsrmmdbd       Media Database
390111  1       tcp      8882 nsrsnmd        Storage Node Management
390439  1       tcp      9740 nsrfa          Remote File Access
390433  1       tcp      9447 nsrjobd        Job Management
390114  1       tcp      7948 nsrdispd       Dispatcher
390438  1       tcp      9633 nsrlogd        Audit Logging
390104  205     tcp      9797 nsrmmd         Media Multiplexor
390104  305     tcp      8917 nsrmmd         Media Multiplexor
390104  405     tcp      9636 nsrmmd         Media Multiplexor

• Remote connections from another system cannot connect to client ports on the NetWorker server:

There operating system firewall on the NetWorker server is blocking some or all the ports in the NetWorker port range, default 7937-9936. 

Ensure that the NetWorker service port range (7937-9936) is open in the operating system firewall. Consult with the operating system documentation and administrator for configuring the operating system firewall.

Other ports may be required depending on the services and purpose of the host. See: NetWorker Processes and Ports

If the issue continues after adjusting OS firewall rules, consult the network administrator to check for external firewalls blocking NetWorker ports.