DCUtR

Configure NAT and port forwarding | IPFS Docs

Fix common connection issues by managing your routers NAT and forwarding ports so other IPFS nodes can interact with your node.

The description says it uses a local node, but I don't think that's implemented.

Thought so, it's the same as WebRTC or wireguard, or mesh networks like yggdrasil, you need one publicly connected peer atleast. I think blossom servers should implement a BYO storage BUD that inplements holepunching through yggdrasil. That seems like the sanest of all approaches.

I'll do it soon-ish I need it for formstr anyways.