What do you mean "act as a server"? Do you have any screenshot to see what exactly is going on?

"act as a server"

I don't know. It's a ZoneAlarm comment.

Normally Firefox is the "client" and it opens and closes connections to send and receive content from servers. The characteristic of a "server" is that it continuously listens for incoming connection requests. That should not be needed for normal browsing; you might need it for video conferencing or screen sharing. I think it's fine to block it. If a site really needs it, I'm sure they will tell you that.

Thinking as a person who has a website, I don't know how I would ask a browser to listen for incoming connections. Firefox has a feature to listen for notifications from a site, but you, the user, need to approve that on a site-by-site basis (a drop-down will appear from the left end of the address bar) when the page tries to set it up. (Web Push notifications in Firefox)

Maybe it's something done through the Flash plugin? You can take more control of Flash by setting it to Click-to-Play ("Ask to Activate"). This will delay Flash from starting on a page until you approve it.

To set "Ask to Activate", open the Add-ons page using either:

• Ctrl+Shift+a
• "3-bar" menu button (or Tools menu) > Add-ons

In the left column, click Plugins. Look for "Shockwave Flash" and change "Always Activate" to "Ask to Activate".

With this setting, when you visit a site that wants to use Flash, you should see a notification icon in the address bar and usually (but not always) one of the following: a link in a black rectangle in the page or an infobar sliding down between the toolbar area and the page.

The plugin notification icon in the address bar typically looks like a small, dark gray Lego block. When the page wants to use a blocked plugin, the icon turns red to alert you to the concern.

If you see a good reason to use Flash, and the site looks trustworthy, you can go ahead and click the notification icon in the address bar to allow Flash. You can trust the site for the time being or permanently.

But some pages use Flash only for tracking or playing ads, so if you don't see an immediate need for Flash, feel free to ignore the notification! It will just sit there in case you want to use it later.

rhhardin said

"act as a server" I don't know. It's a ZoneAlarm comment.

Likely ZA making a fuss due to the Connections opened on loopback (127.0.0.1)

based on a related bug report ZoneAlarm has been doing it since at least 2001 with Mozilla products.

http://kb.mozillazine.org/Connections_established_on_startup_(Firefox)