The sys admin's daily grind: UFW
Lack of Defense
Things were better back then. No way! Charly takes a look back at the bad old firewall days and explains why things are better today – assuming you have the right tools.
Watch out, Granddaddy Charly is about to tell his old war stories again: We had nothing back then. If you were in firewall support, that meant working on the front, in your underwear, at temperatures of minus 20 degrees. And, we used to have to build firewall rulesets using BSD's built-in IPFW tool, which didn't even have stateful packet inspection at the time. People kept locking themselves out of the command center or shooting themselves in the foot.
IPWF led to ipchains, which was a blessing; it was followed in kernel 2.4 by iptables, on which most of today's Linux firewalls are based – although the designated successor, nftables, went missing in action some time ago.
However, you can't teach the troops iptables in five minutes – not even the basic routines, such as allow all outgoing, block all incoming, except for connections on ports 22, 80, and 443. Uncomplicated Firewall [1], UFW is actually a much better choice for building just-so firewalls.
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