How to enable IPv6 in Codespaces?

[HunterXuan]

Select Topic Area

Question

Body

I find that IPv6 is not working properly in codespaces. I create codespaces with different regions and try to run commands to visit IPv6-Only websites, but all failed. I used the following commands to test the IPv6 capability.

curl -v -6 https://google.com

curl -v -6 https://microsoft.com

It seems that the DNS is working properly, since it can resolve the domains. Anybody knows about that? How can I enable IPv6 in codespaces?

*   Trying 2603:1030:c02:8::14:443...
* TCP_NODELAY set
* Immediate connect fail for 2603:1030:c02:8::14: Network is unreachable
*   Trying 2603:1020:201:10::10f:443...
* TCP_NODELAY set
* Immediate connect fail for 2603:1020:201:10::10f: Network is unreachable
*   Trying 2603:1010:3:3::5b:443...
* TCP_NODELAY set
* Immediate connect fail for 2603:1010:3:3::5b: Network is unreachable
*   Trying 2603:1030:b:3::152:443...
* TCP_NODELAY set
* Immediate connect fail for 2603:1030:b:3::152: Network is unreachable
*   Trying 2603:1030:20e:3::23c:443...
* TCP_NODELAY set
* Immediate connect fail for 2603:1030:20e:3::23c: Network is unreachable
* Closing connection 0
curl: (7) Couldn't connect to server

[github-actions[bot]]

🕒 Discussion Activity Reminder 🕒

This Discussion has been labeled as dormant by an automated system for having no activity in the last 60 days. Please consider one the following actions:

1️⃣ Close as Out of Date: If the topic is no longer relevant, close the Discussion as out of date at the bottom of the page.

2️⃣ Provide More Information: Share additional details or context — or let the community know if you've found a solution on your own.

3️⃣ Mark a Reply as Answer: If your question has been answered by a reply, mark the most helpful reply as the solution.

Note: This dormant notification will only apply to Discussions with the Question label. To learn more, see our recent announcement.

Thank you for helping bring this Discussion to a resolution! 💬

[MouadELouichouani]

Hey @HunterXuan, This is expected behavior in GitHub Codespaces.

At the moment, Codespaces does not support outbound IPv6 connectivity. DNS resolution for AAAA records works, but the underlying network stack only has IPv4 egress, which is why you see:
Immediate connect fail … Network is unreachable

What you can do instead:
Use IPv4-only endpoints
Use dual-stack services (IPv4 + IPv6)
Tunnel traffic through an external IPv6-capable host (VPN / proxy)
Run IPv6 tests on a VM or cloud provider that supports IPv6