# K8s cni plugin issue: cni plugin not initialized while kube-flannel is running **URL:** \ **Category:** General Discussions\ **Tags:** network\ **Created:** [May 9, 2023, 10:40am UTC](https://discuss.kubernetes.io/t/k8s-cni-plugin-issue-cni-plugin-not-initialized-while-kube-flannel-is-running/24136 "2023-05-09T10:40:18Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![LongKang\_Fan](https://sea2.discourse-cdn.com/flex016/user_avatar/discuss.kubernetes.io/longkang_fan/32/12482_2.png) [@LongKang\_Fan](https://discuss.kubernetes.io/u/LongKang_Fan)\ **Post date:** [May 9, 2023, 10:40am UTC](https://discuss.kubernetes.io/t/k8s-cni-plugin-issue-cni-plugin-not-initialized-while-kube-flannel-is-running/24136/1 "2023-05-09T10:40:19Z")
Hi, I am new to Kubernetes. After ran `kubeadm init --image-repository registry.aliyuncs.com/google_containers --pod-network-cidr=10.244.0.0/16`, I used `flannel` as my CNI. And it works fine until I ran `kubeadm rest` and `init` again. It came out an error in `journalctl -f`: ```auto May 09 16:56:52 k8s-1 kubelet[3418632]: E0509 16:56:52.835517 3418632 kuberuntime_sandbox.go:72] "Failed to create sandbox for pod" err="rpc error: code = Unknown desc = failed to setup network for sandb ox \"a3d0dad567f549ae1a2b5b81632203f49da0f281e03e78785c956234cf4eea89\": plugin type=\"flannel\" failed (add): failed to delegate add: failed to set bridge addr: \"cni0\" already has an IP address differ ent from 10.244.0.1/24" pod="kube-system/coredns-5bbd96d687-fqnfm" May 09 16:56:52 k8s-1 kubelet[3418632]: E0509 16:56:52.835529 3418632 kuberuntime_manager.go:782] "CreatePodSandbox for pod failed" err="rpc error: code = Unknown desc = failed to setup network for sandb ox \"a3d0dad567f549ae1a2b5b81632203f49da0f281e03e78785c956234cf4eea89\": plugin type=\"flannel\" failed (add): failed to delegate add: failed to set bridge addr: \"cni0\" already has an IP address differ ent from 10.244.0.1/24" pod="kube-system/coredns-5bbd96d687-fqnfm" ``` After searching, I chose to run the following commands: ```auto ifconfig cni0 down ifconfig flannel.1 down ip link delete cni0 ip link delete flannel.1 ``` After that, I got an error shows in `journalctl -f`: ```auto May 09 18:12:05 server kubelet[7762]: E0509 18:12:05.424128 7762 kubelet.go:2760] "Container runtime network not ready" networkReady="NetworkReady=false reason:NetworkPluginNotReady message:Network plugin returns error: cni plugin not initialized" May 09 18:12:10 server kubelet[7762]: E0509 18:12:10.425659 7762 kubelet.go:2760] "Container runtime network not ready" networkReady="NetworkReady=false reason:NetworkPluginNotReady message:Network plugin returns error: cni plugin not initialized" ``` However, I got a running `flannel` pod but `coredns` pods are still pending. And the `cni0` network missed. ```auto [root@server k8s]# kubectl get pods --all-namespaces NAMESPACE NAME READY STATUS RESTARTS AGE kube-flannel kube-flannel-ds-55qbm 1/1 Running 0 39m kube-system coredns-7bdc4cb885-jrrck 0/1 Pending 0 41m kube-system coredns-7bdc4cb885-p4j7h 0/1 Pending 0 41m kube-system etcd-server 1/1 Running 12 41m kube-system kube-apiserver-server 1/1 Running 14 41m kube-system kube-controller-manager-server 1/1 Running 12 41m kube-system kube-proxy-vt9pd 1/1 Running 0 41m kube-system kube-scheduler-server 1/1 Running 12 41m [root@server k8s]# ip a 1: lo: mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: ens192: mtu 1500 qdisc mq state UP group default qlen 1000 link/ether 00:0c:29:72:1a:9a brd ff:ff:ff:ff:ff:ff inet 192.168.39.6/24 brd 192.168.39.255 scope global noprefixroute ens192 valid_lft forever preferred_lft forever inet6 fe80::ad0f:3bd5:2d65:be2d/64 scope link noprefixroute valid_lft forever preferred_lft forever 3: virbr0: mtu 1500 qdisc noqueue state DOWN group default qlen 1000 link/ether 52:54:00:d7:3f:83 brd ff:ff:ff:ff:ff:ff inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0 valid_lft forever preferred_lft forever 4: virbr0-nic: mtu 1500 qdisc pfifo_fast master virbr0 state DOWN group default qlen 1000 link/ether 52:54:00:d7:3f:83 brd ff:ff:ff:ff:ff:ff 10: flannel.1: mtu 1450 qdisc noqueue state UNKNOWN group default link/ether 6a:36:b3:6f:8e:f7 brd ff:ff:ff:ff:ff:ff inet 10.244.0.0/32 scope global flannel.1 valid_lft forever preferred_lft forever inet6 fe80::6836:b3ff:fe6f:8ef7/64 scope link valid_lft forever preferred_lft forever 11: docker_gwbridge: mtu 1500 qdisc noqueue state UP group default link/ether 02:42:80:25:3f:17 brd ff:ff:ff:ff:ff:ff inet 172.18.0.1/16 brd 172.18.255.255 scope global docker_gwbridge valid_lft forever preferred_lft forever inet6 fe80::42:80ff:fe25:3f17/64 scope link valid_lft forever preferred_lft forever 12: br-d4a7d41e15ba: mtu 1500 qdisc noqueue state DOWN group default link/ether 02:42:ca:f4:1f:a7 brd ff:ff:ff:ff:ff:ff inet 172.19.0.1/16 brd 172.19.255.255 scope global br-d4a7d41e15ba valid_lft forever preferred_lft forever 13: br-e06ff2880e2b: mtu 1500 qdisc noqueue state DOWN group default link/ether 02:42:25:39:95:04 brd ff:ff:ff:ff:ff:ff inet 172.20.0.1/16 brd 172.20.255.255 scope global br-e06ff2880e2b valid_lft forever preferred_lft forever 14: docker0: mtu 1500 qdisc noqueue state DOWN group default link/ether 02:42:88:50:92:b3 brd ff:ff:ff:ff:ff:ff inet 172.17.0.1/16 brd 172.17.255.255 scope global docker0 valid_lft forever preferred_lft forever 20: veth65ffc0a@if19: mtu 1500 qdisc noqueue master docker_gwbridge state UP group default link/ether 3a:90:99:cc:f2:99 brd ff:ff:ff:ff:ff:ff link-netnsid 1 inet6 fe80::3890:99ff:fecc:f299/64 scope link valid_lft forever preferred_lft forever ``` ### Cluster information: Kubernetes version: v1.27.1 Cloud being used: (put bare-metal if not on a public cloud) Installation method: yum Host OS: Centos7 CNI and version: flannel v0.21.5 CRI and version: containerd, 1.6.21 ---
**Author:** ![joez](https://sea2.discourse-cdn.com/flex016/user_avatar/discuss.kubernetes.io/joez/32/12799_2.png) [@joez](https://discuss.kubernetes.io/u/joez)\ **Post date:** [June 29, 2023, 4:06am UTC](https://discuss.kubernetes.io/t/k8s-cni-plugin-issue-cni-plugin-not-initialized-while-kube-flannel-is-running/24136/2 "2023-06-29T04:06:03Z")
I got the same issue, couldn’t figure out the root cause, so I restarted the machine, after restarting, the problem was gone. Before that I reset the cluster and re-initiazlize a new one, maybe something was not clean up, which cause the issue ---
**Author:** ![agelosnm](https://sea2.discourse-cdn.com/flex016/user_avatar/discuss.kubernetes.io/agelosnm/32/13274_2.png) [@agelosnm](https://discuss.kubernetes.io/u/agelosnm)\ **Post date:** [September 12, 2023, 8:31pm UTC](https://discuss.kubernetes.io/t/k8s-cni-plugin-issue-cni-plugin-not-initialized-while-kube-flannel-is-running/24136/3 "2023-09-12T20:31:10Z")
F\* me…a simple restart of the node made the trick for me as well. Thanks \<3 ---
**Author:** ![joez](https://sea2.discourse-cdn.com/flex016/user_avatar/discuss.kubernetes.io/joez/32/12799_2.png) [@joez](https://discuss.kubernetes.io/u/joez)\ **Post date:** [March 8, 2024, 2:45am UTC](https://discuss.kubernetes.io/t/k8s-cni-plugin-issue-cni-plugin-not-initialized-while-kube-flannel-is-running/24136/4 "2024-03-08T02:45:02Z")
Ran into this problem again so I spent more time trying to solve it. Although I haven’t been able to pinpoint the root cause yet, I suspect it’s a containerd issue. I can reproduce it with following steps: - kubeadm reset - sudo ip link set cni0 down && sudo ip link delete cni0 - sudo rm -rf /etc/cni/net.d/ - initialize the k8s again with flannel CNI plugin restart `containerd` can solve this issue ```auto sudo systemctl restart containerd ``` See also: [Troubleshooting CNI plugin-related errors](https://kubernetes.io/docs/tasks/administer-cluster/migrating-from-dockershim/troubleshooting-cni-plugin-related-errors/#an-example-containerd-configuration-file) ---
**Author:** ![Max\_Fu](https://sea2.discourse-cdn.com/flex016/user_avatar/discuss.kubernetes.io/max_fu/32/16369_2.png) [@Max\_Fu](https://discuss.kubernetes.io/u/Max_Fu)\ **Post date:** [November 29, 2024, 6:22am UTC](https://discuss.kubernetes.io/t/k8s-cni-plugin-issue-cni-plugin-not-initialized-while-kube-flannel-is-running/24136/5 "2024-11-29T06:22:37Z")
F\*, rebooting the node works for me as well.