NVP vProxy: Registration fails with "vProxy in unstable state, method not allowed. Received an HTTP code: 405"

The NetWorker VMware Protection (NVP) integration is configured with the vProxy Appliance. The vProxy is being registered, and the NetWorker Management Console shows an HTTP warning code 405.

Warning    HH:MM:SS  event    vm proxy  Unable to register NSR VMware proxy '[VPROXY_NAME]': vProxy in unstable state, method not allowed. Received an HTTP code: 405, libCURL message: "", url: "https://[NETWORKER_SERVER_NAME]:9090/api/v1/VproxyEngines/RestEngine/Registration"

The vProxy /opt/emc/vproxy/runtime/logs/vrapid/vrapid-engine.log shows:

YYYY/MM/DD HH:MM:SS TRACE:  rejecting unauthorized request "/api/v1/VproxyEngines/RestEngine/process":
YYYY/MM/DD HH:MM:SS TRACE:  {"Config": {"LogTag": "28", "Username": "admin", "SessionId": "", "IdleTimeout": 300, "LogLevel": "INFO", "Password": "*****", "NWS": "[NETWORKER_SERVER_NAME]", "Cp": "-----BEGIN CERTIFICATE-----\nMIICwD....\n-----END CERTIFICATE-----\n-----BEGIN RSA PRIVATE KEY-----\n.....==\n-----END RSA PRIVATE KEY-----\n", "MobServer": {"HostName": "[VCENTER_SERVER_NAME]", "UserName": "[VCENTER_USER]", "UserPassword": "*****", "TcpPort": 0}}}
YYYY/MM/DD HH:MM:SS ERROR:  AdminEngine: sending response error: code=401, errText=only requests from [NETWORKER_SERVER_NAME] are allowed
YYYY/MM/DD HH:MM:SS TRACE:  rejecting unauthorized request "/api/v1/VproxyEngines":

Use one of the following options:

Solution:

Configure Domain Name System (DNS) entries for all the NetWorker Server interface IP addresses to resolve to the NetWorker Server hostname. The vProxy registration resolves all the IP addresses for the NetWorker Server and adds them to the access control list.
If this is not possible, one of the workaround options must be used.

Workaround 1:

1. Connect to the vProxy appliance over SSH as admin.
2. Switch to root: sudo su - root
3. Edit the systemd unit configuration file: vi /usr/lib/systemd/system/vrapid.service
4. Find the line starting with "ExecStart=/opt/emc/vproxy/bin/vrapid"
5. Append the command-line argument to disable access control.

6. Reload the unit configuration file: systemctl daemon-reload
7. Restart the vrapid engine: systemctl restart vrapid.service
8. Register the vProxy with the NetWorker server.

Workaround 2:

Edit the vProxy /etc/hosts file prior to registration and add all the NetWorker Server interface IP addresses to resolve to the NetWorker Server hostname. 

The following article contains additional steps which may be required: NVP vProxy: How To Unregister/Re-Register a vProxy Appliance?