URL with port number in Firefox

Firefox will block url containing port number for security reasons.
we can configure firefox to access url with port numbers.
we can override the blocked ports as follow:
Solution:
first type "about:config" into the address bar and press Enter.
then right click anywhere on the page and choose choose New -> String.
then type "network.security.ports.banned.override" in the textbox and click OK.
and in the value textbox we can enter port numbers seperated by comma., like 86,87,88
and then click OK.