Windows Azure – Firefox & “Port Restricted for Security Reasons”


I’ve been starting to delve into the world of Windows Azure this week.

After getting the Azure Samples loaded, I tried running one of them (just by hitting F5 in VS) and, as Firefox is my default browser, got a “Port Restricted For Security Reasons” error.

Of course, it worked fine in IE

Here is what to do –

It turns out, that my application was trying to use port 87 on (

Load up Firefox. Type about:config in the address bar, and hit enter. You will get something like the following:


Right click, and click New -> String.

Set the preference name to:

Next, set the value to: 87 (or whatever port your app is using)