Hot answers tagged

15

Someone wrote a Bitcoin protocol decoder for Wireshark, several years ago. I assume it was included in the Wireshark distribution. Wireshark simply knows about the Bitcoin protocol. There is no magic involved.


6

When a node requests one of it's neighbours for a list of it's peers, that node responds with a list of all of it's neighbours. No it doesn't. It responds with list of nodes that its aware of being claimed exist. It likely isn't connected to any of the nodes it returns and probably has never connected to many of them. Many of them may not even be real. (...


5

There are significantly more than 10k full nodes on the network. The 10k figure is simply the number of reachable nodes which listen publicly for new connections. There are many more times that amount which do not have open ports. Luke-jr publishes information about nodes his own knows about[1], suggesting there are in the order of 100k nodes. It only takes ...


5

The oldest version that can sync is 0.8.6. This is the version that first used LevelDB instead of BDB. Both the IRC node discovery and the protocol message changes occurred several versions prior.


4

A node is only called a peer if you're connected to it. So by definition you are always connected to all your peers. I assume you're asking whether you're connected to every node in the network. The answer is no; most Bitcoin node software implementations only connected to around 8 others. What happens if one is malicious? Bitcoin is trust-minimized by ...


4

It returns some plausible peers, not all of its peers. You have no way of knowing any specific details about them, if they’re sybil, not operational, or not useful. The software tries to work out what is most optimal for outgoing connections based on its own criteria, and doesnt trust this information for anything besides a hint towards where other peers ...


3

No, due to different reasons. First, the network is always in flux, nodes are appearing and disappearing, and connections are even more dynamic, so even if there were an API you could use to ask a node for its connections, that information would be outdated quickly. Second, privacy is part of the reason why crypto currencies exist. Divulging the list of ...


3

This is an excellent question but still probably a little bit under specified. Let me try to give an answer and elaborate. When looking at network bandwidth there are several componants playing into it. The most obvious (and probably most dominant) one is specified in BOLT 07 routing-gossip. There are 4 messages which are used to provide the information ...


3

You can use a "network sniffer" to observe data packets on your local network which are sent from or received by your computer. It will be helpful to study the Bitcoin network protocol documentation so that you can define a filter that will only show the Bitcoin related traffic. A popular choice for Windows is Wireshark, but there are many other options. ...


2

Bitcoin is a gossip network and relays transaction or blocks on a best effort basis. Hence you cannot determine the probability of one transaction being seen by the network versus the other. Now in terms of mining the transactions in a block there are a couple of cases that needs to be considered. For assumption sake let us assume that we are considering a ...


2

As difficulty adjusts automatically, it is indeed possible to run a mostly functional network with the bare minimum hardware required for storage and networking. Naturally, this network will have next to no protection against a 51% attack, as anyone with a faster computer (or computers) will easily be able to outdo your bare minimum hardware. Running it ...


2

So can a blockchain can be shutdown by shutting down power supply across the globe? What would happen in such a case? If the world's power supply was suddenly cut off, then everything electronic would stop working. The blockchain would be 'frozen', each node would retain its local copy, but be unable to communicate with other nodes, and miners would be ...


2

The recommended way is to use the -connect option. You can do -connect=0 or -noconnect (they mean the same thing) and Bitcoin Core will not try to automatically connect to any other node.


2

From my understanding, the difficulty of the network will still keep increasing when the "target" block is mined, regardless of the number of miners (yes?) No. The difficulty readjusts every 2016 blocks, based on the average time taken to mine the previous 2016 blocks. If the average is less than 10 minutes, the difficulty goes up. If greater than 10 ...


1

When your client start the connection with another peer it is outbound, otherwise it is inbound. If you want to be sure that your tor node is properly setup and that other peer can connect to you, check: https://en.bitcoin.it/wiki/Setting_up_a_Tor_hidden_service


1

This is not only related to Lightning but remains true for any critical application that you run on your PC when connected to your home network. If your home network is compromised then an attacker can possibly escalate privileges and compromise the machine on which your lightning node is running (as well as other critical applications). Lightning is thought ...


1

Many wallet software obfuscate the information about payment and change address in order to protect the privacy of the user. When you see block explorer websites showing addresses in the outputs as change addresses, they are merely guessing as there is no sure shot way of knowing. Some of the techniques used to identify change addresses are below. I have ...


1

Nodes that participate in the Bitcoin network run a computer program such as this one: https://github.com/bitcoin/bitcoin, which dictates how everything works. To answer your more specific questions: Yes, bitcoin once used UPnP, here are some more details: https://dirkmittler.homeip.net/blog/archives/3340 but in modern versions it does not (thanks for ...


1

This is implementation dependent of course. Afaik every implementation will try to reconnect, so your first case works (note that your paranoid friend's Tor hidden service isn't used at all). This is common in practice, for any non-public node. In the second case, for c-lightning the address hint will be forgotten on reconnect, so they'll try to reconnect ...


1

It is possible that intermediate nodes on the route between you and the payee may track previous payments they have forwarded. If this happens, then the first time the payment_preimage for a payment_hash is revealed, any node along the route could remember it, and if they see the same payment_hash used again in another payment, they would be able to respond ...


1

https://ln.alhur.es/ provides a download link for their historical channel database from this link: https://ln.alhur.es/static/channels.db Data starts June 2019 and provided by https://twitter.com/fiatjaf


1

Here is a simple guide on how to build and run your own home node behind a tor. https://github.com/bitembassy/home-node


1

I havent seen a proper answer on the internet so I did the test myself using bitcoin-0.18.1 with the -testnet flag and after downloading the chain ~2 GB I monitored the traffic of the bitcoind process with nethogs for 24 hours. I got 40MB download and 20MB uploads so 60*30 = 1800MB You can expect 1.8GB of traffic from the bitcoin testnet compared to the ...


Only top voted, non community-wiki answers of a minimum length are eligible