Hello everyone Kubernetes version:v1.21.1 Cloud being used: LAB Private Installation method: repo install Host OS: centos7 CNI: flannel I’ve setup a LAB cluster with 3 node (node1, node2, node3), node 1 is master. I setup environment and join node to cluster done, nodes Ready, But I’ve issue…

What CNI driver are you using? I’ve seen that sort of error before if theres a problem at the CNI level.

yes! I’ve update CNI: flannel

Seems like I’ve issue where. i checked configmap coredns and see it’s forward dns to /etc/resolv.conf. But i don’t have idea to fix, because my nodes is visual machine. I’ve fix hostname in file hosts, but issue not resolved yet.

Quick question on this, are you expecting coredns to observe your node’s /etc/hosts file in this the case? Where are node1, node2, and node3 setup DNS-wise?

Yes. I find method to use coredns hosts file, a idea but i don’t know it’s work Using both hosts and kubernetes plugin doesn't seem working · Issue #1268 · coredns/coredns · GitHub nodes config dns google(8.8.8.8)

Containers don’t use the host’s /etc/hosts file. Each container has it’s own nsswitch configuration. You could probably do something like this . I’m a bit biased here though. If you need to connect to a node to do something on a node, you can just do it directly in a pod. To illustrate how to do it…

May I know how did u fix it right? Facing the same problem here.

@akala515 - I found that my CNI was using iptables-legacy even though my debian 10 VMs were set to use nt_tables. This was causing my rules for 10.96 to be applied to iptables-legacy and iptables-legacy -t nat for CNI and causing this breakage. Resolution for me was to start over, remove all iptabl…

@Brandon_Ojeda I managed to get it working with your instructions ( networking - Kubernetes: unreachable backend: read udp 10.200.0.9:46159->183.60.83.19:53: i/o timeout - Stack Overflow ) + HINFO: unreachable backend: read udp 10.200.0.9:46159->183.60.83.19:53: i/o timeout · Issue #2693 · coredns/cor…

I faced the same issue and resolved it. Details are available here

CoreDNS [ERROR] plugin/errors: 2

General Discussions

letran3691 May 31, 2021, 4:40pm 6

Yes. I find method to use coredns hosts file, a idea but i don’t know it’s work Using both hosts and kubernetes plugin doesn't seem working · Issue #1268 · coredns/coredns · GitHub
nodes config dns google(8.8.8.8)

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CoreDNS [ERROR] plugin/errors: 2

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