[nikisweeting]

Heh, I walked a similar path ~7 years ago. Wanted to get started developing a mesh network routing algorithm that could handle a hundred hops, got distracted and built a mesh networking test harness / simulation system instead (https://github.com/pirate/mesh-networking).

Never got around to finishing a full routing algorithm, though we did have a lot of fun testing wacky network topologies and protocols that solved subsets of the problem.

The closest we came was designing a 2 or 3 tiered system, where nodes self-arrange into clusters of up to 256 nodes with one elected leader to coordinate. The routing table is replicated on all nodes (eventually consistent), but the leader handles all changes. Then there's Layer 2 routing between clusters with a similar leader election system to handle inter-cluster routing.

We tried to figure out a way to make the routing stateless, (e.g. by encoding a node's position in the graph in its id, sort of like a phone number has a country code, then area code, etc.), but stopped working on it before figuring out a good approach for broadcasting ID changes without flooding the network with broadcast traffic beyond small network sizes.

Nowadays there are established mesh routing algorithms that solve all these problems (like B.A.T.M.A.N., Contiki, 802.11s, or even BGP), but it's still a really exciting field that I dream of working in professionally someday.

https://www.open-mesh.org/projects/open-mesh/wiki

[MayeulC]

I currently like https://yggdrasil-network.github.io

AFAIK, each node generates its own key, and keys are then deterministically organized in a tree topology. Then, as you said, there's a lot of established systems. Yggdrasil is from the cjdns lineage.

[rnhmjoj]

Do you know what kind of encryption it uses? I couldn't find any information on this from the site. Yggdrasil looks it could be perfect to set up a simple VPN with zero configuration, but it's hard to trust its cryptography if it's not even documented.

[MayeulC]

There is an overview in the whitepaper: https://github.com/yggdrasil-network/yggdrasil-go/blob/maste...

It fits the "private VPN" use-case quite well in my experience. You can connect to the wider network over the Internet, or just set your nodes up. If yggdrasil is installed on every router, it automatically creates a nice network topology, since it finds peers on the local subnet. Router advertising is also a possibility.

Though there's no real drawback to connecting to the wider network since it's end-to-end encrypted, you have to be aware that specifying more than one peer will make it possible for traffic to be routed trough you, so the whole network performance can be sensitive to the choices that are made when peering over the Internet, as I think hop count is the only metric for now.

For private meshes, I don't think you can specify fallback peer addresses over the Internet, so you have a bit of the same risk here. I've seen some info on mesh wireguard networks with peer information stored in DNS at this year's FOSDEM, but that's currently definitely more configuration than yggdrasil.

End-to-end encryption and the ability to generate your own static, roaming-compatible IPs is nice. I just wish one could open sockets directly with a crypto key rather than the derivated IP.

For more discussion, I can really recommend the Matrix chat room :)

[diggan]

I'm not familiar with Yggdrasil but familiar with cjdns and since there seems to be a lineage, I could tell you that cjdns is using curve25519, xsalsa20, and poly1305. Not sure if that's what Yggdrasil ended up using.

[neilalexander]

Yggdrasil uses curve25519.