Hi, just to find out Main.Menu> How to run telnet command on veritas netbackup appliance after going to Main.Menu> Support > Maintenance> Elevate?
Your appliance "model" might be 5240. As for your appliance "version", you will have to check.
As previously highlighted, within later / recent "versions" of appliance, "telnet" has been removed. It's simply not there, so the answer in your case is probaby: "No, you cannot use telnet."
I have to ask... what kind of site are you working at anyway where they would even consider allowing the use of telnet?
Assuming that you're willing to check the remote port accessibility. Use curl;
curl -v telnet://remote_host_IP:tcp_port
curl -v telnet://172.16.6.51:1556
Telnet is disabled in a lot of environments, but if you're just wanting to test remote port connectivity, you can use netcat
nc -zv <client name> <port number> will show you if a port is open or not when telnet is disabled.
For Windows, use the Test-NetConnection PowerShell cmdlet.