Is IPv6 supported ?

[jmarcgit]

Hi,

I'm asking this because CGNAT is deployed right now. Any experience with that ?

[Caprico85]

Hi,

As far as I know, we don't have anything in the source code that explicitly prevents IPv6. Theoretically, it should work. Practically, I'm currently trying to figure it out. I deleted the A record from my dual-stack setup and left only the AAAA record. Since Google now only knows my IPv6 address, it should access it via IPv6. However, it is still using IPv4. I probably need to wait until Google's DNS caches expire. I'll report back when I know more.

[jmarcgit]

Thank you. I did some tests on my side. I can reach the check page from inside and outside my network using IPv6. I spent HOURS because the online http clients I tested don't work with IPv6. I will pair my server with Google tomorrow and will report here.

update : it works for me

[Caprico85]

After a few days of working with IPv6, I can confirm that it works for me too.

It is noticeably slower than IPv4. But I guess that is something about my network.

[jmarcgit]

@Caprico85 I believe I found potential problems related to local fullfilment. Are you sure the local protocol is still working ?

1- In local mode there is a check of the source ipv6 address. And nodered smarthome will only accept local link Ipv6 addresses. Any connection from a local device throught a global IPv6 will be blocked. It's possible to say if 2 IPv6 are in the same network but it requires a calculation (extract prefix of 2 addresses and compare them). I believe this logic also works for IPv4 (only difference is the address length) so we can write a single function that compares 2 addresses and says if they are in the same subnet or not.

2- Looks like the UDP server is using IPv4 (udp4 is mentionned when creating the socket). This means that IPv4 will also be used to query the express webserver. I switched nodered to IPv6 and it looks like there no IPv4 listening socket anymore in nodered. So I believe UDP advertizing is broken. Maybe we have to check if nodered is started with ipv6 binding and then create an udp6 socket instead ?

3- Maybe MDNS advertizing still works but I'm afraid that the HTTP requests could be blocked because of 1- In my experience avahi is advertzing using a global ipv6 whenever possible.