Can pod-network-cidr and service-cidr overlap outside cluster intranet ips?


Hello, guys! i have a few questions about the pod-network-cidr and service-cidr and maybe someone can help me to understand.

Are these pod-network-cidr and service-cidr internal to the kubernetes cluster only ? Can they interfere with the external network if those addresses overlap addresses outside the cluster ?
Hypothetically speaking, since service-cidr defaults to “”, what would happen if somewhere in my network ( outside the k8s cluster ) i have a router whose ip is ( that belongs to the ?
Thanks for the help!


Hi! We looked at this question during office hours, take a look!


here are the result:

that your Pod network must not overlap with any of the host networks as this can cause issues. If you find a collision between your network plugin’s preferred Pod network and some of your host networks, you should think of a suitable CIDR replacement and use that during kubeadm init with --pod-network-cidr and as a replacement in your network plugin’s YAML.