Note: This bug is displayed in read-only format because
the product is no longer active in Red Hat Bugzilla.
RHEL Engineering is moving the tracking of its product development work on RHEL 6 through RHEL 9 to Red Hat Jira (issues.redhat.com). If you're a Red Hat customer, please continue to file support cases via the Red Hat customer portal. If you're not, please head to the "RHEL project" in Red Hat Jira and file new tickets here. Individual Bugzilla bugs in the statuses "NEW", "ASSIGNED", and "POST" are being migrated throughout September 2023. Bugs of Red Hat partners with an assigned Engineering Partner Manager (EPM) are migrated in late September as per pre-agreed dates. Bugs against components "kernel", "kernel-rt", and "kpatch" are only migrated if still in "NEW" or "ASSIGNED". If you cannot log in to RH Jira, please consult article #7032570. That failing, please send an e-mail to the RH Jira admins at rh-issues@redhat.com to troubleshoot your issue as a user management inquiry. The email creates a ServiceNow ticket with Red Hat. Individual Bugzilla bugs that are migrated will be moved to status "CLOSED", resolution "MIGRATED", and set with "MigratedToJIRA" in "Keywords". The link to the successor Jira issue will be found under "Links", have a little "two-footprint" icon next to it, and direct you to the "RHEL project" in Red Hat Jira (issue links are of type "https://issues.redhat.com/browse/RHEL-XXXX", where "X" is a digit). This same link will be available in a blue banner at the top of the page informing you that that bug has been migrated.
+++ This bug was initially created as a clone of Bug #2103285 +++
This is a clone of bug 2103285.
the summary is:
- cloud-init creates NetworkManager profiles with `ipv6.addr-gen-mode=eui64`. That is good and necessary in the environment of bug 2103285. Note that cloud-init does not explicitly configure eui64 in NetworkManager. But it gets it implicitly, because it does not specify the addr-gen-mode in the files that it writes.
- later, when other interfaces get added, NetworkManager auto generates new profiles for those interfaces and activates them. Those are named "Wired connection 1". Those profiles have `ipv6.addr-gen-mode=default` (which, on most RHEL systems ends up being "stable-private" and not "eui64"). That causes problems for the custome.
In NetworkManager 1.40, the per-profile setting of "ipv6.addr-gen-mode" can be overriden by global-connection-defaults in NetworkManage.conf. See for details the commit message https://gitlab.freedesktop.org/NetworkManager/NetworkManager/-/commit/e6a33c04ebe1ac84e31628911e25bdfd7534dd3c.
This was requested by bug 2082682 for the CoreOS issue https://github.com/coreos/fedora-coreos-tracker/issues/907.
Note that in https://bugzilla.redhat.com/show_bug.cgi?id=2082682#c15 there was also consideration whether this needs to be adressed in cloud-init. So far, it was not, but this report is about doing that.
Choosing addr-gen-mode=eui64 may not be best in all cases. See for example https://github.com/coreos/fedora-coreos-tracker/issues/907#issuecomment-1119911839 .
However, as cloud-init already deploys it profiles with eui64, it seems to have already made that choice. It should go one step further, and deploy a file /etc/NetworkManager/conf.d/30-cloud-init-ip6-addr-gen-mode.conf with content:
# This is generated by cloud-init.
#
[connection.30-cloud-init-ip6-addr-gen-mode]
# Select EUI64 to be used if the profile does not specify it.
ipv6.addr-gen-mode=0
This will work with NetworkManager 1.40.0+, rhel-8.7+, rhel-9.2+
Tested with cloud-init-23.1.1-9.el9(NetworkManager-1.43.9-1.el9.x86_64) on OpenStack, the instance can get ipv6 address and ping successfully, and I think the below test results are expected, setting Verified:Tested
----
# cat /etc/cloud/cloud.cfg
network:
renderers: ['network-manager', 'eni', 'netplan', 'sysconfig', 'networkd']
----
# nmcli -f NAME,FILENAME,DBUS-PATH c show
NAME FILENAME DBUS-PATH
cloud-init eth0 /etc/NetworkManager/system-connections/cloud-init-eth0.nmconnection /org/freedesktop/NetworkManager/Settings/1
lo /run/NetworkManager/system-connections/lo.nmconnection /org/freedesktop/NetworkManager/Settings/2
# cat /etc/NetworkManager/system-connections/cloud-init-eth0.nmconnection
# Generated by cloud-init. Changes will be lost.
[connection]
id=cloud-init eth0
...
[ipv6]
method=auto
may-fail=false
route1=::/0,2620:52:0:84::3fe
# nmcli -o c show /etc/NetworkManager/system-connections/cloud-init-eth0.nmconnection
connection.id: cloud-init eth0
...
ipv4.method: auto
ipv4.may-fail: no
ipv6.method: auto
ipv6.routes: { ip = ::/0, nh = 2620:52:0:84::3fe }
ipv6.may-fail: no
ipv6.addr-gen-mode: default-or-eui64
# cat /etc/NetworkManager/conf.d/30-cloud-init-ip6-addr-gen-mode.conf
# This is generated by cloud-init. Do not edit.
#
[.config]
enable=nm-version-min:1.40
[connection.30-cloud-init-ip6-addr-gen-mode]
# Select EUI64 to be used if the profile does not specify it.
ipv6.addr-gen-mode=0
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.
For information on the advisory (Moderate: cloud-init security, bug fix, and enhancement update), and where to find the updated
files, follow the link below.
If the solution does not work for you, open a new bug report.
https://access.redhat.com/errata/RHSA-2023:6371