请教老师，为什么在我使用的node上无法执行kubectl exec -it 无法进入pod中？

[root@VM-8-15-centos docs]# kubectl get pod -n ingress-nginx
NAME                                        READY   STATUS    RESTARTS   AGE
nginx-ingress-controller-84865c44d9-rxr4p   1/1     Running   0          17m

但是执行exec命令时报错：

[root@VM-8-15-centos docs]# kubectl exec -it nginx-ingress-controller-84865c44d9-rxr4p sh -n ingress-nginx
kubectl exec [POD] [COMMAND] is DEPRECATED and will be removed in a future version. Use kubectl exec [POD] -- [COMMAND] instead.
Error from server: error dialing backend: dial tcp 172.16.0.11:10250: i/o timeout

然后为了研究是哪里出了问题，我检查到底是什么问题。于是，找到6-2nginx-deplyment.yaml 创建的pod实验，执行：

[root@VM-8-15-centos docs]# kubectl get pod -o wide
NAME                        READY   STATUS    RESTARTS   AGE   IP            NODE             NOMINATED NODE   READINESS GATES
my-nginx-6d97ddfff5-cwbl2   1/1     Running   0          99m   10.244.1.11   vm-0-11-centos   <none>           <none>
my-nginx-6d97ddfff5-wgxjp   1/1     Running   0          99m   10.244.2.20   vm-8-15-centos   <none>           <none>

但是执行exec的时候也都是timeout

[root@VM-8-15-centos docs]# kubectl exec -it my-nginx-6d97ddfff5-wgxjp sh
kubectl exec [POD] [COMMAND] is DEPRECATED and will be removed in a future version. Use kubectl exec [POD] -- [COMMAND] instead.
Error from server: error dialing backend: dial tcp 10.0.8.15:10250: i/o timeout
[root@VM-8-15-centos docs]# kubectl exec -it my-nginx-6d97ddfff5-cwbl2 sh
kubectl exec [POD] [COMMAND] is DEPRECATED and will be removed in a future version. Use kubectl exec [POD] -- [COMMAND] instead.
Error from server: error dialing backend: dial tcp 172.16.0.11:10250: i/o timeout