can not access to IPv6 Internet

[lancersky2017]

Describe the bug A clear and concise description of what the bug is.
Hi experts,
I formed a Thread network according to the documentation https://openthread.google.cn/codelabs/openthread-border-router-nat64#0

~# ot-ctl state
leader
Done
~# ot-ctl ipaddr
fdde:ad00:beef:0:0:ff:fe00:fc11
fdde:ad00:beef:0:0:ff:fe00:fc10
fdde:ad00:beef:0:0:ff:fe00:fc38
fdc9:58d8:8547:1:686:10fc:8fad:c1ca
fdde:ad00:beef:0:0:ff:fe00:fc00
fdde:ad00:beef:0:0:ff:fe00:3c00
fdde:ad00:beef:0:7fef:ca83:4a41:a6bd
fe80:0:0:0:24b5:6dbc:892:4bf3
Done
~# ot-ctl netdata show
Prefixes:
fdc9:58d8:8547:1::/64 paos low 3c00
Routes:
fdc9:58d8:8547:2:0:0::/96 sn low 3c00
fdf5:9feb:1392:231::/64 s med 3c00
Services:
44970 01 2b000500000e10 s 3c00
44970 5d fddead00beef00007fefca834a41a6bdd121 s 3c00
Done
~# ot-ctl nat64 state
PrefixManager: Active
Translator: Active
Done

And I successfully tested NAT64/DNS64 with an NRF52840 USB dongle.

> version
OPENTHREAD/thread-reference-20200818-2312-g242c7cc7c; NRF52840; Feb 16 2023 10:56:03
Done
> ping 8.8.8.8
Pinging synthesized IPv6 address: fdc9:58d8:8547:2:0:0:808:808
16 bytes from fdc9:58d8:8547:2:0:0:808:808: icmp_seq=33 hlim=115 time=64ms
1 packets transmitted, 1 packets received. Packet loss = 0.0%. Round-trip min/avg/max = 64/64.0/64 ms.
Done
> dns resolve4 gitlab.com 8.8.8.8
Synthesized IPv6 DNS server address: fdc9:58d8:8547:2:0:0:808:808
DNS response for gitlab.com. - fdc9:58d8:8547:2:0:0:ac41:fb4e TTL:300 
Done
> ping fdc9:58d8:8547:2:0:0:ac41:fb4e
16 bytes from fdc9:58d8:8547:2:0:0:ac41:fb4e: icmp_seq=34 hlim=54 time=201ms
1 packets transmitted, 1 packets received. Packet loss = 0.0%. Round-trip min/avg/max = 201/201.0/201 ms.
Done
> ping 192.168.18.203
Pinging synthesized IPv6 address: fdc9:58d8:8547:2:0:0:c0a8:12cb
16 bytes from fdc9:58d8:8547:2:0:0:c0a8:12cb: icmp_seq=36 hlim=63 time=15ms
1 packets transmitted, 1 packets received. Packet loss = 0.0%. Round-trip min/avg/max = 15/15.0/15 ms.
Done

But the MTD node can not access to IPv6 Internet. And I grab wpan0 with tcpdump without any packets.
Even if I turn nat64 off it doesn't work.

> dns resolve gitlab.com 8.8.8.8
Synthesized IPv6 DNS server address: fdc9:58d8:8547:2:0:0:808:808
DNS response for gitlab.com. - 2606:4700:90:0:f22e:fbec:5bed:a9b9 TTL:300 
Done
> ping 2606:4700:90:0:f22e:fbec:5bed:a9b9
1 packets transmitted, 0 packets received. Packet loss = 100.0%.
Done

I checked that OTBR is able to access the IPv6 network.

~# ping 2606:4700:90:0:f22e:fbec:5bed:a9b9
PING 2606:4700:90:0:f22e:fbec:5bed:a9b9 (2606:4700:90:0:f22e:fbec:5bed:a9b9): 56 data bytes
64 bytes from 2606:4700:90:0:f22e:fbec:5bed:a9b9: seq=0 ttl=55 time=241.518 ms
64 bytes from 2606:4700:90:0:f22e:fbec:5bed:a9b9: seq=1 ttl=55 time=241.962 ms
64 bytes from 2606:4700:90:0:f22e:fbec:5bed:a9b9: seq=2 ttl=55 time=241.422 ms
^C
--- 2606:4700:90:0:f22e:fbec:5bed:a9b9 ping statistics ---
5 packets transmitted, 3 packets received, 40% packet loss
round-trip min/avg/max = 241.422/241.634/241.962 ms

~# ping -6 gitlab.com
PING gitlab.com (2606:4700:90:0:f22e:fbec:5bed:a9b9): 56 data bytes
64 bytes from 2606:4700:90:0:f22e:fbec:5bed:a9b9: seq=0 ttl=55 time=189.532 ms
64 bytes from 2606:4700:90:0:f22e:fbec:5bed:a9b9: seq=1 ttl=55 time=189.199 ms
64 bytes from 2606:4700:90:0:f22e:fbec:5bed:a9b9: seq=2 ttl=55 time=189.630 ms
^C
--- gitlab.com ping statistics ---
3 packets transmitted, 3 packets received, 0% packet loss
round-trip min/avg/max = 189.199/189.453/189.630 ms

To Reproduce Information to reproduce the behavior, including:

1. Git commit id OTBR base on GSDK4.2.1
2. IEEE 802.15.4 hardware platform
3. Build steps
4. Network topology

Expected behavior A clear and concise description of what you expected to happen.

Console/log output If applicable, add console/log output to help explain your problem.

Additional context Add any other context about the problem here.

[wgtdkp]

Accessing of global IPv6 internet is not supported by OT/OTBR yet.

[jwhui]

I think it's more accurate to say that OTBR does not support automatic global IPv6 configuration. It is possible to manually configure or add some additional services that can configure for global IPv6 connectivity.

[marcorussi]

Hi, could you please name a service that I can use for doing this? Thank you.

[jwhui]

Configuring global IPv6 connectivity requires:

1. Acquiring a global IPv6 prefix for the Thread network.
2. Configuring the Thread network with the global IPv6 prefix from (1).

For (1), your ISP needs to provide sufficient IPv6 prefixes for your network (e.g. one for Wi-Fi, one for Thread). Ideally, the Thread Border Router can use DHCPv6 Prefix Delegation to obtain the prefix.

[lancersky2017]

The ISP assigned me an IPv6 address prefix, and I configured it to Ethernet and Thread network.
I can access the global IPv6 network from the Ethernet side but fail from the Thread network.

[kianooshkarami]

Accessing of global IPv6 internet is not supported by OT/OTBR yet.

Could you share where we could track when that functionality is planned for and how we could track it?

[jwhui]

Automatic configuration for global IPv6 connectivity is currently being standardized within the Thread Group.

[maxminard]

@jwhui Do we have any updates on when Thread Group might plan for global IPv6 connectivity standardization?

[jwhui]

It's coming soon: https://www.threadgroup.org/News-and-Events/ID/634/Threads-2024-Enhancements-and-What-Theyll-Mean-to-You