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

Natao arisiva ity resaka mitohy ity. Mametraha fanontaniana azafady raha mila fanampiana.

Firefox Ports Outbound: 50000 - 65535

  • 1 valiny
  • 1 manana an'ity olana ity
  • 4 views
  • Valiny farany nomen'i cor-el

more options

Why does Firefox use dynamic ports in the 50K+ range when I use it to browse the web?

I have included screen shots with netstat -AB as well as currports.

Furthermore, if I set a rule in Windows Firewall blocking outbound traffic on ports 50000 - 65535, it breaks DNS with Firefox, even though 53 UDP is open.

I'm not overly concerned with any connection that is localhost / 127.0.0.1.

I've tried prohibiting these ports by modifying user.js - No impact, only works if I implicitly call out the port (example.com:55000)

What do? Why is FF using these ports?

Why does Firefox use dynamic ports in the 50K+ range when I use it to browse the web? I have included screen shots with netstat -AB as well as currports. Furthermore, if I set a rule in Windows Firewall blocking outbound traffic on ports 50000 - 65535, it breaks DNS with Firefox, even though 53 UDP is open. I'm not overly concerned with any connection that is localhost / 127.0.0.1. I've tried prohibiting these ports by modifying user.js - No impact, only works if I implicitly call out the port (example.com:55000) What do? Why is FF using these ports?
Sarin'efijery napaingotra

All Replies (1)

more options