Merge pull request #24223 from howieyuen/dns-config

[zh] reconcile dns config

Author: k8s-ci-robot

content/zh/docs/tasks/administer-cluster/dns-custom-nameservers.md

@@ -151,12 +151,11 @@ data:
         ready
         kubernetes cluster.local in-addr.arpa ip6.arpa {
            pods insecure
-           upstream
            fallthrough in-addr.arpa ip6.arpa
            ttl 30
         }
         prometheus :9153
-        proxy ./etc/resolv.conf
+        forward ./etc/resolv.conf
         cache 30
         loop
         reload