Do I need to configure my firewall to run Bitcoin?

Do I need to configure my firewall to run Bitcoin?

Bitcoin will connect to other nodes, usually on TCP port 8333. You will need to allow outgoing TCP connections to port 8333 if you want to allow your Bitcoin client to connect to many nodes. Testnet uses TCP port 18333 instead of 8333.

If you want to restrict your firewall rules to a few IPs, you can find stable nodes in the fallback nodes list.

• GENERAL

• What is bitcoin?
• What are bitcoins?
• How can I get bitcoins?
• Does Bitcoin guarantee an influx of free money?
• Is Bitcoin a 'get-rich-quick' scheme?
• Will I make money by installing the client?
• As an investment, is Bitcoin a sure thing?
• Can I buy bitcoins with Paypal?
• Where can I find a forum to discuss Bitcoin?
• How are new bitcoins created?
• What's the current total number of bitcoins in existence?
• How divisible are bitcoins?
• What do I call the various denominations of bitcoin?
• How does the halving work when the number gets really small?
• How long will it take to generate all the coins?
• If no more coins are going to be generated, will more blocks be created?
• But if no more coins are generated, what happens when Bitcoins are lost? Won't that be a problem?
• If every transaction is broadcast via the network, does Bitcoin scale?

• ECONOMY

• Where does the value of Bitcoin stem from? What backs up Bitcoin?
• Is Bitcoin a bubble?
• Is Bitcoin a Ponzi scheme?
• Doesn't Bitcoin unfairly benefit early adopters?
• Won't loss of wallets and the finite amount of Bitcoins create excessive deflation, destroying Bitcoin?
• What if someone bought up all the existing Bitcoins?
• What if someone creates a new block chain, or a new digital currency that renders Bitcoin obsolete?
• Is Bitcoin open to value manipulation?

• SENDİNG AND RECEİVİNG PAYMENTS

• Why do I have to wait 10 minutes before I can spend money I received?
• Do you have to wait until my transactions are confirmed in order to buy or sell things with Bitcoin?
• I was sent some bitcoins and they haven't arrived yet! Where are they?
• I sent too small of a transaction fee, is my bitcoin lost forever?
• Why does my Bitcoin address keep changing?
• How much will the transaction fee be? Why is the fee so high?
• What happens when someone sends me a bitcoin but my computer is powered off?
• How long does "synchronizing" take when the Bitcoin client is first installed? What's it doing?

• NETWORKING

• Do I need to configure my firewall to run Bitcoin?
• How does the peer finding mechanism work?

• MINING

• What is mining?
• Is mining used for some useful computation?
• Is it not a waste of energy?
• Why don't we use calculations that are also useful for some other purpose?
• How can we stop miners from creating zero transaction blocks?
• How does the proof-of-work system help secure Bitcoin?
• Why was the "Generate coin" option of the client software removed?

• SECURITY

• Could miners collude to give themselves money or to fundamentally change the nature of Bitcoin?
• Could miners gang up and give themselves money?
• Can they do so in ways not sanctioned by Bitcoin network? Is there any way to rip off the network and make loads of money dishonestly?
• Could miners fundamentally change the nature of bitcoin?