I am running bitcoind on the latest Ubuntu 12.10 Quantal Quetzel on amazon’s EC2 network.
The security group I have attached to the box only allows port 22 so I can login via ssh.
How is bitcoind able to operate, then?
I started up bitcoind and it says it has 8 connections and is actively downloading blocks… but how? When port 22 is the only opened port on my box?
Your firewall allows outgoing connections.
Bitcoind creates 8 outgoing connections (by default), over port 8333.