Bitcoin Forum

Hey everyone!

I have a question regarding IPv6 nodes. According to websites such as bitnodes.io (http://bitnodes.io), there are +1000 active IPv6 nodes and +6000 active IPv4 nodes (not counting  the nodes behind .onion addresses).

How many of the IPv6 nodes are actually dual-stack nodes, providing access via IPv4 and IPv6? In other words, how many of the IPv6 nodes are also counted in the set of IPv4 nodes?

I wonder if this can be determined or at least estimated somehow.
If there is no good way to accurately answer this question, what do people in the forum think? How do you run your node(s)?

Thanks in advance for any information you can share!

I doubt it. Bitcoin node have very few behavior which could be fingerprinted. For example, pruned node on Bitcoin Core only serve latest 288 blocks to prevent fingerprint even if they store far more block.


I can't even make a guess when it's also possible to use both IPv4/IPv6 and Tor.

Is this just something you'd like to know "for fun" or are you curious about how decentralised cryptocurrency is.

I don't think it matters if the same node is listening to ipv6, ipv4 and/or tor at the same time because, if it isn't, you could just have multiple nodes run by the same person doing that anyway and that'll be close to the same thing.

There is no way to know for sure. But as a *guess* I would say 95+% are dual-stack. That would be keeping with the 95+% of IP6 being dual stacked.
As of late late last year less then 5% of places on the net were IP6 only. And most of those were cloud / hosted services.

No matter how hard people try to kill it, IP4 is going to keep on going.

-Dave

Thanks a lot for your answers!
I agree with Dave that probably most nodes that offer an IPv6 endpoint are dual-stacked.


I'm working with IPv6-only machines and I'm wondering if there could be a security risk when connecting only to the advertised IPv6 addresses.

For example, if the number of IPv6 nodes is small and these node are separate machines, an attacker might try to get them all to extend a fork. However, if these machines are part of the IPv4 network as well, this risk is reduced because the nodes still obtain the proper blocks.

Does anybody see security risks when running IPv6-only machines?

Thanks for your reply!

Nearly every data-center server has both IPV4 and IPV6 enabled, which represents the majority of full nodes. So the data is probably counted twice (or even three times, if it also advertises a TOR address).

Yes with a few buts.
1) Is the firewall setup to pass IPV6?
2) The server may have ACCESS to IPV6 but did the admin actually put in values?
3) Is the BTC node configured to use IPV6
4) Does the node operator know or care.
5) More that I can't think of at the moment.

-Dave

I would add that maybe many of those people running nodes on both address types, are doing it just because they don't know how to keep only one of them. It happened to me in the past. Also, there was something else happening which was to be running behind tor, but I was ending up always with 2 onion addresses. I don't remember now why it was happening but I think it had something to do with a config from Tor service itself and then, another config from the node!