Is there a personal firewall for Linux / Ubuntu?

Question

I am looking for some kind of personal firewall for Linux, that will monitor all outgoing connections and show me a message asking for permission to open that connection. Like the popular personal firewalls for Windows.

Does something like this exist?

Solution 1

Firestarter or Guarddog would be the friendliest GUI interface to iptables.

• Firestarter
• Guarddog

But the short of it is... No, there doesn't seem to be an all-in-one firewall programme with popup notification.

< ubottu> Ubuntu, like any other linux  distribution, has firewall capabilities built-in. The firewall is managed using the 'ufw' command (see 
            https://help.ubuntu.com/community/Uncomplicated_Firewall_ufw), or 'iptables' (https://help.ubuntu.com/community/IptablesHowTo). GUI 
            applications such as Firestarter/Gufw (Gnome) or Guarddog (KDE) also exist

Solution 2

Firestarter will show you in real-time what applications are doing what, the closest thing I know of to a Linux equivalent of ZoneAlarm (Windows) or Little Snitch (Mac OS X) is this proof of concept.

Personally tend to use FireHOL, locking down everything to begin with, and then adding applications that require Internet access one by one. If you locked down port 80 and only permitted Firefox to send traffic to destination port 80 you'd have the equivalent of only permitting Firefox to access the Internet.

It's fairly straightforward with FireHOL to deny everything by default and only permit access on a per-application (or per-user) basis. You might want to allow the root user to access using any application, but individual users can only access the Internet using specified applications, or specified ports.

Update: FireFlier looks like it will do the trick. But it's no longer in development so YMMV.

Solution 3

Consider looking into Leopard Flower at sourceforge.net/projects/leopardflower/

It does what you were asking for except it is CLI application

Solution 4

Check out the Ubuntu server guide on firewalls.

Solution 5

I've looked for such a thing but haven't found one (yet)... in principle it might be possible to implement this using the nfnetlink_queue functionality in IPtables, but I think that's relatively new, so I wouldn't be entirely surprised that there's no program that takes advantage of it yet.

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Comments

[Admin]

try looking at firestarter as a gui front end for iptables.

[GaVinci]

I know about ufw, I am interesting in stalling the connection while popping up a dialog for the user which asks for permission to allow the connection. Preferably on a per. application basis, so the user is able to allow a specific application and not just open a specific tcp/udp port.

[Steve Townsend]

FYI, it is most certainly still under active development by Novell/SuSE.

[Al Baker]

+1 for info on where to look for a DIY approach.

[David Z]

Thanks, although I'm not sure it exactly qualifies as DIY... I once tried to write the program but it turned out to be rather involved. I'd love to get back to it someday if only I had time...

[Taha Jahangir]

Both are out-of-date