Known issues

MKE 3.5.5 known issues with available workaround solutions include:


[FIELD-5081] Node Feature Discovery Pods cause crash loop

Use of Node Feature Discovery (NFD) Pods can result in a crash loop in Linux systems that run MCR 20.10.8 and earlier (moby/moby#42836).

Workaround:

Update MCR to version 20.10.9 or later.


[MKE-8914] Windows Server Core with Containers images incompatible with GCP

As Windows Server Core with Containers images are not compatible with GCP, their use will prevent kubelet from starting up.

Workaround:

Use Windows Server or Windows Server Core images.


[MKE-8814] Mismatched MTU values cause Swarm overlay network issues on GCP

The default MTU value for GCP VPCs is 1460 and the default MTU value for Docker networks is 1500. When left unchanged, components that use Swarm overlay networks fail to communicate with each other.

To workaround the issue, select from the following options:

  • Create a new VPC and set the MTU value to 1500.

  • Set the MTU value of the existing VPC to 1500.

For more information, refer to the Google Cloud Platform documentation, Change the MTU setting of a VPC network.


ucp-kube-proxy container can mistakenly present as unhealthy in eBPF mode

When running Calico in eBPF mode with kube-proxy disabled, the ucp-kube-proxy container can erroneously display an unhealthy status, which you can safely ignore. The specific settings in the MKE configuration file that can produce this result are as follows:

calico_ebpf_enabled = true
kube_proxy_mode = "disabled"

For more information about these settings, refer to Cluster and service networking options and Configure cluster and service networking in an existing cluster.


[MKE-9110] IPVS mode is inoperable on kernel version 5.11 or later

Kube-proxy in IPVS mode is inoperable when running MKE on kernel version 5.11 or later. A workaround solution is available upon request.