[SalesForce] Unable to Authorize Salesforce org using SFDX : Trailhead

Please install Salesforce DX plugin using the following command and then try to authorize

sfdx plugins:install salesforcedx@48.22.11

This works for me.

Administered Port Exclusions are the reason.

In the Salesforce CLI log, you also see:

error: listen EACCES: permission denied 127.0.0.1:1717

Run this in a Cmd Prompt:

> netsh interface ipv4 show excludedportrange protocol=tcp

Protocol tcp Port Exclusion Ranges

Start Port    End Port
----------    --------
        80          80
       443         443
       808         808
      1068        1167
      1168        1267
      1268        1367
      1473        1572
      1573        1672
      1673        1772
      5357        5357
     11821       11920
     11921       12020
     12263       12362
     12363       12462
     12463       12562
     12563       12662
     16013       16013
     20807       20807
     22221       22221
     22223       22223
     37408       37408
     50000       50059     *

* - Administered port exclusions.

You can see port 1717 is in a blocked range (1673 to 1772) I changed mine to 1771 by ading this line to sfdx-project.json:

"oauthLocalPort": "1771",

and it worked OK - sort of.

In the Browser, I still got the error:

But, when I looked, I saw it was still trying to use pot 1717. I edited the URL in the browser to the new Port I had selected (1771 in my case - yours may be different) and it worked - the callback to VS Code completed and I was logged in to SF and could down load my code.

See https://stackoverflow.com/questions/58216537/what-is-administered-port-exclusions-in-windows-10 for more about 'Administered Port Exclusions'