Setting SecureCRT as default telnet handler for EVE-NG devices on Firefox.

While doing Lab practice on EVE-NG's Web GUI on Firefox Web-browser, telnet (by double click or right-click console option) to a network device opens Ubuntu's default terminal (Gnome Terminal) via 'xdg-open' script from 'xdg-utils' by default. Console to multiple devices opens a new instance of Gnome Terminal for each telnet session, which for me is not handy and makes it too messy! 

I'm rather a SecureCRT fan, and have always preferred it over other available terminal emulators due to it's awesome features and handy tools. So, I was trying to find a way to open the EVE-NG's telnet:// or ssh:// links directly via SecureCRT. Manual telnet/SSH from SecureCRT to EVE-NG's devices works fine by default, but, this becomes hectic for full scale CCIE Labs having over 50 or more devices running.

With the help of VanDyke Technical Support, I was able to figure out a way to get Firefox on Ubuntu to prompt you for which application to open SSH/Telnet links with.

Following instructions can make it possible:

• Open Firefox and type “about:config” in address bar.
• Create a new Boolean preference (right click on an empty space), name it
  “network.protocol-handler.expose.telnet” (without inverted commas) for telnet handler, and set the value “false”.
• Create another new Boolean preference (right click on an empty space), name it
  “network.protocol-handler.expose.ssh” (without inverted commas) for ssh handler, and set the value “false”
• Restart the browser.

This should be enough for Firefox to let us select an external application to open “telnet://” links. 
While testing I would suggest leaving the "Remember my choice for ..." option unchecked. When prompted you should be able to select SecureCRT, by default it is located at /usr/bin/SecureCRT.

PS:
I'm using latest SecureCRT 8.3.2 on Ubuntu 16.04.4 LTS (Xenial) and while attempting various suggested workarounds, messed up SecureCRT's Tab feature (it kept opening new sessions in new instances rather than in tabs).

There is a work around that you could try. It would force SecureCRT into Single Instance mode, though you would not be able to open two separate instances of SecureCRT.

To accomplish this:

• Locate the config folder info in the General / Configuration Paths category of SecureCRT's Global Options
• Close all instances of SecureCRT/FX
• Navigate to your SecureCRT configuration folder
• Locate and open the Global.ini file
• Find the line containing "Single Instance"
• Modify the line to D:"Single Instance"=00000001
• Save the changes to Global.ini

Now that SecureCRT is in Single Instance mode any link selected should open in a new tab.

HTH,
Rana Tauqeer.