Configuring a NSH Proxy Server
The NSH Proxy Server can be used to restrict NSH access so that a NSH client must first authenticate to the TrueSight Server Automationapplication server before connecting to the manged system. Direct connections from the NSH clients on the user's workstations is not allowed, and all NSH connections to the managed servers will come from the TrueSight Server Automation application server(s).
In this example, we are going to:
- Configure the Network Shell (NSH) Proxy Service on the Application Server
- Configure a managed server to accept connections from only the NSH Proxy.
- Configure a NSH client on a client workstation to connect to a managed server through the NSH proxy
Scenario Configurations
For this scenario we have:
- TrueSight Server Automation/NSH Proxy Server (TrueSight Server AutomationApplication Server)
- TrueSight Server Automation/NSH Proxy Client
- Managed Server
Steps
Configure the Network Shell (NSH) Proxy Service on the Application Server
Infrastructure Management
- From the TrueSight Server AutomationClient, connect to an Application Server in the environment and open Infrastructure Management.
- Assuming this instance is an 'ALL' profile type, right-click the application server and select Edit.
- Set ProxySvcPort to 9842.
Configure the NSH client on the applications server to use this NSH proxy (optional)
Modifying the secure file
Before making changes to the file, make a backup of the secure file.
Run the following Command:
secadmin -m default -p 5 -appserver_protocol ssoproxy -T encryption_only -e tls- After running the above command appserver_protocol=ssoproxy entry will be available in secure file (in rsc folder). The file can also be directly edited in a text editor instead of using secadmin.
Restart the Application Server Service
On the applications server where changes were made, restart the Application Server Service.
Configure a managed server to accept connections from only the NSH Proxy.
On the managed server perform the following steps:
Updating the users file
Make sure that the nouser entry is available in the users file (of rsc folder) on the other machines where you want to access using an NSH command. Typically the nouser entry will exist in the file if ACLs are being pushed from TrueSight Server Automation.
Updating the exports file
In the exports file ensure you have only an entry for the application server's host name or IP address and no other entries.
Confirming access restriction
From your NSH client system, open up a NSH window and run:
This indicates that there is no access from your NSH client system.
Configure a NSH client on a client workstation to connect to a managed server through the NSH proxy
On a client workstation that has the TrueSight Server Automation GUI installed perform the following steps.
Modifying the secure file
Run the following Command:
Creating an Authentication Profile
If the Authentication Profile defaultProfile does not exist, create it, either from the first screen of the TrueSight Server Automation gui or with the blcred command
Where:
- APPSERVER is the application server hostname or IP address
- AUTH_SERVICE_PORT is the port the authentication service is listening on (9840 by default)
- AUTH_TYPE is the authentication type for the user login (for example, SRP)
Getting credentials
There are two ways to get the credentials for use with the NSH Proxy
Via the GUI
After launching the TrueSight Server Automation GUI, click on the Options>> button and ensure the Save Credential for this session box is checked.
Via blcred
Verify Access to managed system
Now run the same agentinfo command you ran before and see the successful result.
Tip:
Do not forget to destroy the cache credential once you are done running nsh commands. The following image shows how to destroy (delete) a cache credential.
