IPv6 Support

[CMCDragonkai]

Specification

IPv4 is being exhausted, and much of the new internet will be ipv6 only.

The PK agent should support binding, listening and connecting to IPv6 addresses.

Currently we're limited in several ways:

1. The utp-native has no IPv6 support
2. NAT busting hasn't been tested with IPv6 (what kind of NAT architectures would exist for IPv6)
3. DHT hasn't been tested with IPv6
4. CLI option parsing hasn't been tested with IPv6
5. Our AWS NLB which runs the testnet and mainnet does not yet support IPv6 with UDP protocol
6. AWS VPC/subnets hasn't been tested with IPv6 or configured with IPv6 assignments
7. Our GRPC server (and perhaps client service in general) hasn't been tested with dual stack assignments, supporting IPv6 means we should still listen on IPv4 at the same time (but this requires documentation of the options)

All of the above has to be solved to support IPv6.

Additional context

• Using QUIC/HTTP3 to replace utp-native for the Data Transfer Layer in the networking domain #234 - replacing utp-native with quic would allow IPv6
• Testnet Node Deployment (testnet.polykey.io) #194 - notes on IPv6 work in AWS and the relevant PR Testnet Deployment via CI/CD #396
• https://github.com/MatrixAI/js-polykey/issues/153 - IPv6 also has their own multicast domains
• https://stackoverflow.com/questions/47797322/node-js-server-only-listening-on-ipv6
• https://www.grouparoo.com/blog/node-js-and-ipv6

Tasks

1. Add tests to Node Connection to test local IPv6 usage
2. Enable IPv6 on the testnet
3. Apply integration tests to the testnet infrastructure
4. IPv6 supported by quic layer.
5. IPv6 supported by websocket layer.
6. IPv6 discovery with MDNS.
7. IPv6 supported by nodeGraph.

[CMCDragonkai]

RPC is no longer limited to IPv4, it can do IPv4 or IPv6.

The question of IPv6 is actually more pertinent to QUIC or WebSockets, however I think these should work without any problems.

More testing is required for the nodes domain to ensure that IPv6 is working too.

We're no longer using any load balancer in AWS.

@tegefaulkes can add more details here.

[tegefaulkes]

The agnostic RPC doesn't care about transport so long as it's a bi-directional UInt8Array. So yeah, the IPv6 support comes down to the websocket and quic implementations. I think both should be able to support it.

[CMCDragonkai]

Testing for IPv6 is relevant for agent migration.

[CMCDragonkai]

Isn't this part of the agent migration @tegefaulkes?

[tegefaulkes]

I can add it to #535 , Though I think IPv6 support is added by just using js-quic now. So it's something to check.

[tegefaulkes]

For this to be considered done, we'd need to support IPv6 on every level. We need to track the IPv6 address in the nodeGraph. Possibly as part of #537. The websocket transport layer needs to support it, I think it can so likely that's a simple change. Lastly we'd want to discover 'local' IPv6 addresses with the MDNS system.