What is Firefox doing when it tries to connect to these addresses...
"detectportal.firefox.com is used to detect captive portals on public wifi networks to be able to redirect you to their logon screen, so you don't just get page loading errors in firefox (set network.captive-portal-service.enabled to false in about:config in order to disable that feature). shavar.services.mozilla.com is used to update the list of trackers that are getting blocked when tracking protection is turned on. secure.fanboy.co.nz will be used by your adblocking addon to update its filter lists.
i would suspect that all of these connections only have a negligible impact on your normal browsing."