From Fedora Project Wiki

The problem with a static firewall as Fedora currently ships with iptables/system-config-firewall is that it actively interferes with a lot of things that users want to do with their desktops:

  • mDNS related sharing:
    • Discovering any remote services (music, screen, printer, etc. shares and .local hosts)
    • Music sharing (via DAAP, in Rhythmbox, Banshee, etc.)
    • Personal File sharing (WebDAV, through gnome-user-share)
    • Desktop sharing (VNC, through vinagre)
    • Remote disk management (udisks and gnome-disk-utility)
    • Local network chats (Pidgin, Empathy)
  • UPNP related:
    • DLNA music/movies/photos sharing (in Rygel, mediatomb, etc.)
  • Other:
    • Automatic discovery of printers and other services (CUPS specific)
    • ssh

Possible ways to improve the situation are:

  • Just turn the firewall off. Rely on not running any unnecessary network-facing services, and lock the necessary services down using SELinux.
  • Allow applications to poke holes in the firewall, under user-control
  • Handle different situations differently: no firewall when on the trusted 'home network', but strict firewall when using coffee shop wifi

Related bugs

Other OSes

  • Ubuntu's firewall is disabled by default
  • Mandriva's firewall has the same problem as Fedora's (they use shorewall)