How to remove Firefox's "This address is restricted", commonly triggered by trying to access port 87

Here is a quick guide on how to remove Firefox's error message when trying to access resources on restricted ports, such as port 87:

This address is restricted

This address uses a network port which is normally used for purposes other than Web browsing. Firefox has canceled the request for your protection.

1 Open Firefox's settings: about:config

Open Firefox's preferences by typing the following URL in Firefox:

about:config

2 Find the settings network.security.ports.banned.override

In the Filter box, type in network.security.ports.banned.override

3 Create if not found

If you can't find such a preference, right click to open up the pop-up menu and pick New and then String.

As preference name type network.security.ports.banned.override and 87 as the value.

Afterwards it should look something like this:

4 Modify if exists, and how to add multiple ports

If such a preference already exists, you can specify multiple ports. Either as a range such as 1-1024 or even combine with a comma separated list such as 87, 150-300, 350, 400, 450-500.

5 Refresh the page

Just refresh the page and you should have no problems accessing the resource.

Old comments from Disqus

Sriharsha CR, Sunday, May 18, 2014 1:28 PM

Good Idea.., I've set the sting value 1-1024 & that's working... Thank U :)

Bomyne, Thursday, May 15, 2014 10:55 AM

Thanks. This was annoying when it first started to me just now as it was blocking FTP.