Join the AMA (Ask Me Anything) with the Firefox leadership team to celebrate Firefox 20th anniversary and discuss Firefox’s future on Mozilla Connect. Mark your calendar on Thursday, November 14, 18:00 - 20:00 UTC!

This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

why does firefox start extremely slowly when i set my firewall to allow outgoing connections only?

  • 5 پاسخ
  • 1 has this problem
  • 1 view
  • آخرین پاسخ توسّط cor-el

more options

When I configure my Firewall on Windows to allow outgoing connections only for firefox.exe, then Firefox hangs during startup and comes up after 30 or 60 seconds.

When I let all traffic pass through, it starts immediately.

I cannot see any listeing port in tcpview. So I wonder: Why does firefox hang when only outgoing connections are allowed?

When I configure my Firewall on Windows to allow outgoing connections only for firefox.exe, then Firefox hangs during startup and comes up after 30 or 60 seconds. When I let all traffic pass through, it starts immediately. I cannot see any listeing port in tcpview. So I wonder: Why does firefox hang when only outgoing connections are allowed?

Chosen solution

All Replies (5)

more options

Basically, Firefox is allowed to send, but not receive. Set the firewall for two-way.

more options

This does not explain anything.

more options

Firefox is a web browser. It displays what it is sent. If it does not receive anything, there is nothing to display.

more options

FredMcD, please!

A browser normally requires outgoing connections only, it opens a tcp connection to the web server and downloads the file. I had Firefox configured to allow outgoing connections only for many years. But something changed, some part of firefox requires "incoming" that is "listening" connections (i am not sure you know the difference between incoming and outgoing connections in firewall terms).

maybe firefox requires even some udp, do not know. please take a step back and lets wait until someone else can say something about that.

more options

Chosen Solution