Add `ipfs stats network` command to tell you if your node is publicly reachable

[2color]

Checklist

• My issue is specific & actionable.
• I am not suggesting a protocol enhancement.
• I have searched on the issue tracker for my issue.

Description

Problem

Users currently have no easy way to determine if their IPFS node is publicly reachable. Indeed, you can use the ipfs id to see your IP addresses, however, due to circuit relay multiaddrs and the many transports, it's not very user friendly. There are also situations when ipfs id returns a public IP that isn't in fact reachable.

Proposed Solution

Add ipfs stats network command that:

1. Reports reachability status: public, private, or relayed (if you have circuit relay reservations.
2. Shows the external IP address(es) and port(s) other peers can reach you on
3. Uses AutoNAT for determining the output

Example Output

$ ipfs stats network

Public Reachability: public
External Addresses:
  - /ip4/203.0.113.42/tcp/4001/p2p/...
  - /ip6/2001:db8::1/tcp/4001/p2p/...

AutoNAT Status: public (confirmed by 3/5 peers)

Note: We could also return JSON

Where this might be useful

This can help a lot in the IPFS docs for debugging information and guides focused on publishing data where this matters for retrieval without NAT traversal.

[lidel]

Thanks for opening this, @2color. This would be useful for docs and debugging.

Command Location

I'd suggest ipfs swarm addrs autonat since ipfs swarm addrs already has local and listen subcommands. Adding autonat there fits naturally: "show me address reachability as determined by AutoNAT".

AutoNAT v2 Per-Address Reachability

Good news: go-libp2p v0.46+ exposes per-address reachability verified by AutoNAT v2 via BasicHost.ConfirmedAddrs() (basic_host.go). This returns three slices: reachable, unreachable, and unknown addresses.

Note:

• this is different from Host.Addrs() which just returns announced addresses without the per-address verification status
• since Autonat V1 is being sunset at some point, we should only expose v2 results here

If you go AutoNAT v2 route, you would have better detail than just "external addrs":

$ ipfs swarm addrs autonat

AutoNAT V2 Status:
  Reachability: public

Per-Address Reachability:
  Reachable:
    /ip4/203.0.113.42/tcp/4001
    /ip4/203.0.113.42/udp/4001/quic-v1
  Unreachable:
    /ip6/2001:db8::1/tcp/4001
  Unknown:
    /ip4/203.0.113.42/udp/4001/webrtc-direct

As for --help of this new command, good to mention https://github.com/libp2p/specs/blob/master/autonat/autonat-v2.md there.

Implementation pointers

Add a new subcommand to swarmAddrsCmd.Subcommands in core/commands/swarm.go.

To get the data, you'll likely need a type assertion since ConfirmedAddrs() is on BasicHost, not the Host interface:

if bh, ok := nd.PeerHost.(*basichost.BasicHost); ok {
    reachable, unreachable, unknown := bh.ConfirmedAddrs()
}

Same with Reachability() for overall reachability status (public/private/unknown). We already read it, you can see prior art in telemetry.go.

Happy to review a PR if you want to give this a shot.