Ubuntu host firewall

There was a port I wanted to protect with some firewall rules on my mythtv box.

I begain to wonder – as ubuntu often causes me to – what is the RIGHT way to do this? With slackware I would just ass some iptables rules to a script and add it to rc.local – but this seems a bit too primitive for Ubuntu – where there are complex system abstracting every startup task!

Quick research showed that for using an ubuntu as a firewall for other machines that shorewall was the ticket – but I wanted something simpler. I learned ubuntu has ufw for this – but I was still not impressed.

After remembering something a coworker showed me I searched further and I found the and found the slicehost initial setup howto for Gutsy Gibbon. Under iptables they have a perfectly simple system.

Add this to /etc/network/interfaces on the “lo” interface after the line "iface lo inet loopback”

pre-up iptables-restore < /etc/iptables.up.rules

Then populate iptables.up.rules with the ip-tables-save command after creating some rules with iptables -A


iptables-save > /etc/iptables.up.rules

Once you have saved a few rules you might be able to modify this file manually - it is similar to the options of the iptables command but less forgiving. test with
iptables-restore < /etc/iptables.up.rules



Today I Hate: Adobe AIR for Linux Alpha

Adobe released a version of Air for Linux as an Alpha. http://labs.adobe.com/downloads/air_linux.html

And since I wanted to try out an inane twitted based air app I thought I would give it a go.

I followed common sense – then the instruction manual(!) trying to install Adobe Air but all I could get was the helpful:

An error occurred while installing Adobe AIR. Installation may not be allowed by your administrator. Please contact your administrator.

I asked myself for permission but I didn’t know how to grant it to myself! It was making me feel pretty inadequate – I would normally consider myself a capable system administrator – especially of my own damn PC.

Google was not my friend today either.. At least not directly. Eventually in my hunting I did learn than internally Adobe Air uses dpkg (or rpm) to install – it was using package management.

I suddenly realised I had Synaptic running! Cosing it solved the problem immediately.

If you are having the same problem make sure you closed any package management tools – they will lock the package database and stop the install.

Sure it was the bleeding obvious but I still maintain that was a piss weak error message.

I don’t really hate Adobe AIR for Linux Alpha – It is just that ranting about what you hate sounds much funnier than moaning about a small hiccup.