# How many full IOTA nodes are there, and how many do there need to be?

How many full nodes are there currently in the network? Are there any sites that track the currently connected nodes in real-time?

Leading on from this - which should perhaps be a separate question - is there a minimum number of nodes which is required to keep the network secure?

• I think the first half of the question is not so good because it is always going to be changing. The second half, however is good and should be the question, rather than another question.
– user253
Nov 28, 2017 at 22:58

# Nobody can count the amount of full nodes

(Because of that, there are also no sites that track them)
Why?

Every square is a full node. Connected nodes are neighbours.

• F has 3 Neighbours: E, H and G.
• F knows is that there are at least 4 nodes in the network.
• F does not know how many or which neighbours E, H or G have.
• F has no idea that J or C or D even exist

That's why you can't and never will be able to count the full nodes in the system.

# Minimum Number of full nodes

Theoretically IOTA could run on a single full node with all light clients connected to it. This wouldn't make a lot of sense though, because it wouldn't be decentralized and therefore not secure. 2 nodes would be more secure, 3 nodes even more secure and so on. The more full nodes, the more secure.

• With two or three nodes there'd always be at least one node who is all-knowing. Even though they might not know that they are. That suggests a lower limit of at least four nodes to reach the conclusion of the first part of your answer. Nov 29, 2017 at 22:23
• I'm not quite sure what you mean by that but you can edit the answer.
– Zauz
Nov 29, 2017 at 22:27
• But don't those full nodes have to be used in order to add security? And in order to get used, there should be a public registry?
– w00t
Dec 13, 2017 at 12:26
• What do you mean by „using a full nofe“ and „adding security“? No, there should never be a public registry. Attackers shouldn‘t be able to know how nodes are connected.
– Zauz
Dec 13, 2017 at 12:47

IOTA can theoretically run perfectly fine with just a single node.

However, in current stress tests, it seems like nodes can handle about 1000 TPS. So for more than that, there would need to be more nodes.

Keep in mind that currently, the coordinator limits the throughput of IOTA, so the number may vary from the above until it is changed.

To answer the question of security, a single node isn't secure. Security increases with the amount of nodes -- an attacker needs to be able to control 34% of the network in order to make a malicious attack, so the more nodes, the less possible this becomes. Security is therefore bound by how powerful any given attacker may be, divided by .34.

• Does that single node run securely? That's the question, not if the network functions theoretically. Nov 29, 2017 at 21:21