While I guess I can see how in Mozilla's mind the automatic connections are not a bug, the documentation bug is undeniable. A documentation page contains information that is simply inaccurate and incomplete. I believe that they closed this bug prematurely just because you pissed them off. I finally managed to partially replicate some of your results, which I have shared along with a request to reopen the bug.
I posted as soon as I had some results to show because I did not want to delay any longer, but I am still struggling to fully replicate your results. Would you mind clarifying some things for me? My procudure was to reboot, start tcpdump, open Firefox (having started with a fresh download of Firefox 58 and followed the steps on the documentation page in question), close Firefox, and stop tcpdump. Your tcpdump command as specified in the bug report was # tcpdump -i eth1 ip src host pc and dst host not router and dst host not pc -ltq Since I am using WiFi and not Ethernet I changed it to # tcpdump -i wlan2 ip src host pc and dst host not router and dst host not pc -ltq which gave me "tcpdump: unknown host 'router'", so I removed 'and dst host not router' # tcpdump -i wlan2 ip src host pc and dst host not pc -ltq This gave no errors or warnings, but it also did not show any connections. I had to remove the boolean expressions: # tcpdump -i wlan2 -ltq To get any output, which showed connections to cloudfront.net. After removing the arguments '-ltq' # tcpdump -i wlan2 and examining the output I was able to find some additional urls among the full output, which I listed in my comment requesting that the report be reopened. So while I can verify that Firefox makes some automatic connections, your results seem a little different from mine, and I'd like to figure out how to replicate more of your results so that I can make a stronger argument in the Mozilla thread. Some differences between my procedure and yours are that I am using Trisquel 8 instead of OpenSUSE and i3 instead of Plasma, but I do not see a particular reason why this should make a difference. It is more likely that I am doing something wrong because I am not as proficient with tcpdump as you are. It is also possible that I am confusing this specific test with some of the other situations you have tested and that I need to try more situations that simply opening and closing the browser (robots.txt etc.) I have not tried these yet because I am very pressed for time at the moment and believe that showing automatic connections on startup and closing should be enough to justify reopening the bug report, but I can try them if you think it will significantly strengthen our case.
