Can the Bitcoin client be used without any incoming ports being opened?


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? -confused


Posted 2013-04-08T22:17:02.687

Reputation: 797



Your firewall allows outgoing connections.

Bitcoind creates 8 outgoing connections (by default), over port 8333.

Stephen Gornick

Posted 2013-04-08T22:17:02.687

Reputation: 26 454

So I am currently leeching from the Bitcoin network, but not helping it propagate transactions? Is that correct? – user3145 – 2013-04-08T22:27:27.740

1@user3145: You are helping to propagate transactions between the 8 nodes you've made outbound connections to, but that's it. I believe the Bitcoin network has no capacity shortage though, so there's no need to go to special efforts to contribute. – David Schwartz – 2013-04-09T01:38:46.960