[Release-1.27] - flannel-v6.1 MAC address changes every boot

[thomasferrandiz]

Backport fix for flannel-v6.1 MAC address changes every boot

• flannel-v6.1 MAC address changes every boot #9957

[fmoral2]

Validated on Version:

-$k3s version v1.27.14+k3s-331ce706 (331ce706)

Environment Details

Infrastructure
Cloud EC2 instance

Node(s) CPU architecture, OS, and Version:
Ubuntu
AMD
DUAL STACK

Cluster Configuration:
-3 nodes

Steps to validate the fix

1. start k3s with flannel-backend: vxlan
2. reboot node A
3. Validate that flannel ipv6 mac addrs is not changed
4. Validate other nodes can communicate
5. Validate nodes and pods

Reproduction Issue:

 
 k3s version v1.28.10+k3s-7b8f0e1b (7b8f0e1b)
 

 ip link show flannel-v6.1
 flannel-v6.1 MAC address: [redacted]-1

 reboot
ip link show flannel-v6.1
 flannel-v6.1 MAC address: [redacted]-23


NODE B AND C:
 $ ping6 0000:cafe:00::

no connection

Validation Results:

  ip link show flannel-v6.1
 flannel-v6.1 MAC address: [redacted]-1f

 reboot
ip link show flannel-v6.1
 flannel-v6.1 MAC address: [redacted]-1f


 NODE B and C:

 $ ping6 0000:cafe:00::
 
 
--- 0000:cafe:00:: ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2009ms
rtt min/avg/max/mdev = 0.248/0.526/0.992/0.331 ms

$ kubectl get nodes,pods -A
NAME                                                STATUS   ROLES                       AGE    VERSION
node/ip- .us-west-1.compute.internal     Ready    control-plane,etcd,master   111m   v1.27.14+k3s-331ce706
node/ip- 1.us-west-1.compute.internal   Ready    <none>                      110m   v1.27.14+k3s-331ce706
node/ip- .us-west-1.compute.internal    Ready    control-plane,etcd,master   113m   v1.27.14+k3s-331ce706
node/ip- .us-west-1.compute.internal    Ready    control-plane,etcd,master   111m   v1.27.14+k3s-331ce706

NAMESPACE     NAME                                                 READY   STATUS      RESTARTS      AGE
default       pod/dualstack-ing-ds-6s7t9                           1/1     Running     1 (55s ago)   110m
default       pod/dualstack-ing-ds-bqvlh                           1/1     Running     0             110m
default       pod/dualstack-ing-ds-hnpgx                           1/1     Running     0             110m
default       pod/dualstack-ing-ds-pw6q9                           1/1     Running     0             110m
default       pod/dualstack-nodeport-deployment-587ddc5c79-8g4z2   1/1     Running     0             109m
default       pod/dualstack-nodeport-deployment-587ddc5c79-9swcn   1/1     Running     0             109m
default       pod/dualstack-nodeport-deployment-587ddc5c79-pcmsr   1/1     Running     1 (55s ago)   109m
default       pod/dualstack-nodeport-deployment-587ddc5c79-whbc7   1/1     Running     0             109m
default       pod/httpd-deployment-fd556997-l77tt                  1/1     Running     0             109m
default       pod/httpd-deployment-fd556997-xhqx7                  1/1     Running     0             109m
kube-system   pod/coredns-77ccd57875-8kjvq                         1/1     Running     1 (55s ago)   113m
kube-system   pod/helm-install-traefik-5fjvl                       0/1     Completed   1             113m
kube-system   pod/helm-install-traefik-crd-sz9d4                   0/1     Completed   0             113m
kube-system   pod/local-path-provisioner-79ffd768b5-b459j          1/1     Running     1 (55s ago)   113m
kube-system   pod/metrics-server-c44988498-cbgbm                   1/1     Running     1 (55s ago)   113m
kube-system   pod/svclb-traefik-75181ac7-2wl2m                     2/2     Running     2 (55s ago)   113m
kube-system   pod/svclb-traefik-75181ac7-4wm7h                     2/2     Running     0             111m
kube-system   pod/svclb-traefik-75181ac7-g5k56                     2/2     Running     0             110m
kube-system   pod/svclb-traefik-75181ac7-mq25f                     2/2     Running     0             111m
kube-system   pod/traefik-7d5c94d587-k6ks2                         1/1     Running     1 (55s ago)   113m