What does a node do?

[Jet Cash]

I gather that once I have downloaded the blockchain, I will be running as a node every time I start Bitcoin core. So what will my computer be doing? As I will be using public WiFi until I finish my project (and maybe for some time afterwards), I won't be contributing a lot to the community, so what can my computer do?

Will it be supplying blocks to other users downloading the blockchain?
Will I be part of the transaction verification process?
What other services will I be able to contribute?

[1714651558]

1714651558

[1714651558]

1714651558

[1714651558]

1714651558

[ranochigo]

By running a full node, you are basically enforcing the network rules by making sure that blocks and transactions follow the rules that the client have set.  You will also be relaying transactions and blocks( when not running autoprune) to the peers, whether you open port 8333 or not. If you open port 8333, more users will be able to connect to you.

You will be part of the verification process. Each full node verifies the validity of the signature and the UXTO before relaying it.

[Jet Cash]

Windows firewall says that Bitcoin core can use any port - should I change that to be port specific, or just leave it alone?

[Amph]

Windows firewall says that Bitcoin core can use any port - should I change that to be port specific, or just leave it alone?

you need to change it to 8333 like it was said and allow outbounds connections, if you want to run a full node

[shorena]

Windows firewall says that Bitcoin core can use any port - should I change that to be port specific, or just leave it alone?

That sounds alright for Windows, but in order to allow connections from the outside the WiFi router would have to point to your device. E.g. you sit at McD and get free WiFi from their router. Lets assume its just a simple SoHo device for simplicity sake. That router has a public IP on one side, this is the IP your computer uses to talk to others in the bitcoin network. On the other side is has internal IP addresses one for each of the devices in the store. If you establish the connection from the inside those from the outside can just answer. Like with a phone call[1] you already have an existing connection if you called the other party. They dont need to call you back or something like that to reply. You can just speak back and forth. In order for someone to estabish a connection to your specific machine, the public IP is not enough. The router must also know if someone asks for "bitcoin core on TCP port 8333" on their public IP that its your laptop and your laptop only that will answer this. Chances are you will not be able to confirgure this on a public WiFi, but it might happen. Bitcoin core has a setting called "Map port using UPnP" (Settings -> Options -> Network) that will try to open the port on the router for you.

Windows firewall says that Bitcoin core can use any port - should I change that to be port specific, or just leave it alone?

you need to change it to 8333 like it was said and allow outbounds connections, if you want to run a full node

Even if you dont accept outbound connections you are a full node. Even if you dont have the full blockchain available (pruned) you are a full node. A full node is any device on the network that enforces the network rules. A full node verifies all data it gets, checks if its according to the rules and relays it unless its considered nonStandard or invalid.

A pruned node can not help others to sync up to the latest block though.

A full node that is not accepting outside connections can not be used by other wallets (like multibit) to gather data about the current state of the network.


[1] TCP connections are only virtual fixed connections over paket based IP and dont actually have a fixed line reserved for them as phone lines would before VoIP.

[ironbit]

A node is just a normal bitcoin client. it does exactly the same as your local installed bitcoin client.

[zodiac3011]

A node is just a normal bitcoin client. it does exactly the same as your local installed bitcoin client.

it has some different functions I think. A node is able to verify the block validity and help people sync blockchain. It's a bitcoin client but with advanced functions

[Amph]

you need to change it to 8333 like it was said and allow outbounds connections, if you want to run a full node

Even if you dont accept outbound connections you are a full node. Even if you dont have the full blockchain available (pruned) you are a full node. A full node is any device on the network that enforces the network rules. A full node verifies all data it gets, checks if its according to the rules and relays it unless its considered nonStandard or invalid.

A pruned node can not help others to sync up to the latest block though.

A full node that is not accepting outside connections can not be used by other wallets (like multibit) to gather data about the current state of the network.


[1] TCP connections are only virtual fixed connections over paket based IP and dont actually have a fixed line reserved for them as phone lines would before VoIP.
[/quote]

i know that if you have only 8 connections going on you're not running a full node

i have only 8 connection here https://bitnodes.21.co/ it tell me that i'm unreachable

[ranochigo]

you need to change it to 8333 like it was said and allow outbounds connections, if you want to run a full node

Even if you dont accept outbound connections you are a full node. Even if you dont have the full blockchain available (pruned) you are a full node. A full node is any device on the network that enforces the network rules. A full node verifies all data it gets, checks if its according to the rules and relays it unless its considered nonStandard or invalid.

A pruned node can not help others to sync up to the latest block though.

A full node that is not accepting outside connections can not be used by other wallets (like multibit) to gather data about the current state of the network.


[1] TCP connections are only virtual fixed connections over paket based IP and dont actually have a fixed line reserved for them as phone lines would before VoIP.

i know that if you have only 8 connections going on you're not running a full node

i have only 8 connection here https://bitnodes.21.co/ it tell me that i'm unreachable

A full node is defined as a client which verifies and enforces network rules.[1]

Bitnodes.21.co connects to your client to check if anyone can connect to your node. Without changing any codes, you are allowed a maximum of 8 outgoing connections. By opening port 8333, you are allowing users to connect to your node. Opening TCP 8333 is definitely great but it's good enough if you just run it. Your peers will still be getting blocks and transactions from you.

[1] https://en.bitcoin.it/wiki/Full_node

[Amph]

you need to change it to 8333 like it was said and allow outbounds connections, if you want to run a full node

Even if you dont accept outbound connections you are a full node. Even if you dont have the full blockchain available (pruned) you are a full node. A full node is any device on the network that enforces the network rules. A full node verifies all data it gets, checks if its according to the rules and relays it unless its considered nonStandard or invalid.

A pruned node can not help others to sync up to the latest block though.

A full node that is not accepting outside connections can not be used by other wallets (like multibit) to gather data about the current state of the network.


[1] TCP connections are only virtual fixed connections over paket based IP and dont actually have a fixed line reserved for them as phone lines would before VoIP.

i know that if you have only 8 connections going on you're not running a full node

i have only 8 connection here https://bitnodes.21.co/ it tell me that i'm unreachable

A full node is defined as a client which verifies and enforces network rules.[1]

Bitnodes.21.co connects to your client to check if anyone can connect to your node. Without changing any codes, you are allowed a maximum of 8 outgoing connections. By opening port 8333, you are allowing users to connect to your node. Opening TCP 8333 is definitely great but it's good enough if you just run it. Your peers will still be getting blocks and transactions from you.

[1] https://en.bitcoin.it/wiki/Full_node

well then everyone is running a full node, because we need to sync after all, but then why there are so few fullnode?

[achow101]

well then everyone is running a full node, because we need to sync after all, but then why there are so few fullnode?

No, full nodes are nodes the store the blockchain and fully verify every single block and transaction they receive. Most people use SPV wallets which do not do that. They rely on full nodes to do the verification for them.

[Jet Cash]

Is there any reward for verifying these transactions, or is it just the miners that get the rewards?

[achow101]

Is there any reward for verifying these transactions, or is it just the miners that get the rewards?

Only miners get transactions fees. Running a full node does not have a reward, which is mostly why people don't run full nodes.

[ranochigo]

well then everyone is running a full node, because we need to sync after all, but then why there are so few fullnode?

Full nodes verifies transaction's validity and relay transactions. SPV clients do not. They trust that the client and miners are following the network rules. The main disadvantage of using a full node is due to the size. Not everyone(including me) is willing to shell out 58GB+ of space for the entire blockchain. Blockchain pruning disables the wallet which doesn't give the user a reason to use Bitcoin Core over SPV clients.

Is there any reward for verifying these transactions, or is it just the miners that get the rewards?

Full nodes do not get any incentives on protocol level. On the external side, [urlhttps://bitnodes.21.co/nodes/incentive/]bitnodes.21.co[/url] is offering a bit of incentives for running a stable full node.

[Jet Cash]

The drive on this machine is 2TB, so I've got space for the blockchain. What I can't guarantee is that I will be online for more than 2 or 3 hours per day.

[Amph]

well then everyone is running a full node, because we need to sync after all, but then why there are so few fullnode?

No, full nodes are nodes the store the blockchain and fully verify every single block and transaction they receive. Most people use SPV wallets which do not do that. They rely on full nodes to do the verification for them.

i know that, i was referring to those that are using core, if everyone of those people are opening core just for synching that they should be counted as a full node, but unless the usage of core is very restricted, it seems that the number of node is not reflecting this

[Appuned]

I use the Core Client, is it a full node? From the above comment, I do not have to open port 8333 to be full node? Does the full node require static IP?

[shorena]

I use the Core Client, is it a full node?

Yes.

From the above comment, I do not have to open port 8333 to be full node?

No. It will allow outbound connections if you do, which will let you hold more than 8 connections in total.

Does the full node require static IP?

No. You might need a static local IP if you forward the port 8333 via your router, but that depends on the router you use. Your external IP can change as it does with most home connections.

[Jet Cash]

I've just read Satoshi's original paper, and I'm still not clear of the difference between a full node and a miner who is just verifying transactions.

[shorena]

I've just read Satoshi's original paper, and I'm still not clear of the difference between a full node and a miner who is just verifying transactions.

A full node must not mine, but a miner must have a full node (or a pool that has one) to determine the current valid state of the blockchain. Miners verify the latest block and try to build a new block which should include unconfirmed and verified transactions. If a miner does not verify the data they can run into grave problems. If the miner does not verify an invalid transaction and they find a block with it, the block will be rejected by other miners when they try to verify it. Thus the block will be an orphan, discarded by the network and the miner will have wasted energy.

Some miners actually dont verify a block they get, assume its correct and continue to mine on top of it. This is dangerous for the network in general as it can lead to a split of the blockchain. The term that was coined for that is "SPV Mining" and you can read more about that here -> https://bitcointalk.org/index.php?topic=1274066.0