Bug 2092459 - IPv6-enabled EC2 subnets always have dhcp enabled
Summary: IPv6-enabled EC2 subnets always have dhcp enabled
Keywords:
Status: CLOSED ERRATA
Alias: None
Product: Fedora
Classification: Fedora
Component: cloud-init
Version: rawhide
Hardware: Unspecified
OS: Unspecified
unspecified
unspecified
Target Milestone: ---
Assignee: Major Hayden 🤠
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2022-06-01 15:28 UTC by Major Hayden 🤠
Modified: 2023-05-17 13:36 UTC (History)
9 users (show)

Fixed In Version: cloud-init-23.1.2-7.fc39
Clone Of:
Environment:
Last Closed: 2023-05-17 13:36:11 UTC
Type: Bug
Embargoed:


Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Fedora Pagure cloud-sig issue 382 0 None None None 2022-06-01 15:28:42 UTC
Launchpad 1976526 0 None None None 2022-06-01 15:28:42 UTC

Description Major Hayden 🤠 2022-06-01 15:28:42 UTC
A Fedora user opened an issue[0] about an issue with cloud-init on EC2. When they launch an instance on a IPv6-enabled subnet, cloud-init sets the `ipv6.method` to `dhcp` in NetworkManager.

However, AWS uses router advertisements to let instances know about the nearest router. Using the `ipv6.method: dhcp` setting prevents router advertisements from working. The instance ends up with an IPv6 address assigned, but it cannot route traffic.

A workaround is to run NetworkManager commands to fix the issue:

```
nmcli con edit CONNECTION_UUID
nmcli> set ipv6.method auto
nmcli> save
nmcli> activate
```

The instance immediately routes IPv6 traffic after making that change. The dhcp setting appears to be applied automatically for EC2 subnets with IPv6 addresses assigned[1].

I would expect `ipv6.method` to be `auto` in these situations.

Thank you!

[0] https://pagure.io/cloud-sig/issue/382
[1] https://github.com/canonical/cloud-init/blob/53a995e2f852d043d51ad25c1b9afbbe1edafd57/cloudinit/sources/DataSourceEc2.py#L861-L863

Comment 1 Ben Cotton 2022-08-09 13:17:10 UTC
This bug appears to have been reported against 'rawhide' during the Fedora Linux 37 development cycle.
Changing version to 37.

Comment 2 Major Hayden 🤠 2023-03-28 21:15:28 UTC
Still waiting on upstream to fix this here: https://bugs.launchpad.net/cloud-init/+bug/1976526

Comment 3 Major Hayden 🤠 2023-03-28 22:25:37 UTC
PR made to patch cloud-init: https://src.fedoraproject.org/rpms/cloud-init/pull-request/29

Comment 4 Fedora Update System 2023-05-17 13:34:30 UTC
FEDORA-2023-8d4d62dfd2 has been submitted as an update to Fedora 39. https://bodhi.fedoraproject.org/updates/FEDORA-2023-8d4d62dfd2

Comment 5 Fedora Update System 2023-05-17 13:36:11 UTC
FEDORA-2023-8d4d62dfd2 has been pushed to the Fedora 39 stable repository.
If problem still persists, please make note of it in this bug report.


Note You need to log in before you can comment on or make changes to this bug.