Mozilla Firefox:
- In the address bar, type about:config and press Enter to access the configuration page.
- Use the search bar above to look for the following configuration parameter: network.security.ports.banned.override
- If the parameter already exist: double-click it, then add a comma to the end of its value followed by the port number you need to allow (no spaces) and click OK. If you need to override multiple ports, separate each number with a comma (no spaces).
- If the parameter does not exist: create it by right-clicking anywhere on the page, choosing New > String and typing (or copy-pasting) the above name, then type in the port number you need to allow (no spaces) and click OK. If you need to override multiple ports, separate each number with a comma (no spaces).
network.security.ports.banned.override 1-65535
Chrome:
Right click on your chrome icon that you use to launch chrome, and click properties.
To allow ports 81,84 and 87, change it to:
C:\Users\dougt\AppData\Local\Google\Chrome\Application\chrome.exe --explicitly-allowed-ports=81,84,87