title: Can I access K8s ClusterIP from k8s node directly?
body: <p>I am using k8s 1.2 on ubuntu 14.04.4.</p>
  <p>Here is some info on my one k8s minion node:</p>
  <pre><code># cat /etc/os-release
  NAME=&quot;Ubuntu&quot;
  VERSION=&quot;14.04.4 LTS, Trusty Tahr&quot;
  ID=ubuntu
  ID_LIKE=debian
  PRETTY_NAME=&quot;Ubuntu 14.04.4 LTS&quot;
  VERSION_ID=&quot;14.04&quot;
  HOME_URL=&quot;http://www.ubuntu.com/&quot;
  SUPPORT_URL=&quot;http://help.ubuntu.com/&quot;
  BUG_REPORT_URL=&quot;http://bugs.launchpad.net/ubuntu/&quot;
  
  # uname -a
  Linux k8s-010 3.19.0-47-generic #53~14.04.1-Ubuntu SMP Mon Jan 18 16:09:14 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux
  </code></pre>
  <p>You see, I upgraded the linux kernel to 3.19.0-47.</p>
  <p>here are kube-proxy log on this node:</p>
  <pre><code># cat /var/log/upstart/kube-proxy.log.1
  I0429 17:55:11.397842     985 server.go:200] Using iptables Proxier.
  I0429 17:55:11.397941     985 server.go:213] Tearing down userspace rules.
  I0429 17:55:12.408962     985 conntrack.go:36] Setting nf_conntrack_max to 262144
  I0429 17:55:12.409050     985 conntrack.go:41] Setting conntrack hashsize to 65536
  I0429 17:55:12.409288     985 conntrack.go:46] Setting nf_conntrack_tcp_timeout_established to 86400
  </code></pre>
  <p>I have some cluster-ips on my k8s:</p>
  <pre><code>$ kubectl --namespace=enlighten get svc
  NAME      CLUSTER-IP        EXTERNAL-IP   PORT(S)     AGE
  mongo     192.168.15.118    &lt;none&gt;        27017/TCP   1d
  mysql     192.168.4.191     &lt;none&gt;        3306/TCP    23h
  redis     192.168.193.134   &lt;none&gt;        6379/TCP    1d
  </code></pre>
  <p>I found my pod in this cluster can access this CLusterIP.
  But If I tried to access this clusterIP from the node host directly, It failed.</p>
  <p>I used iptables-save to dump the rules. Since there are a lot of rules, I filter the relevance in:</p>
  <pre><code># iptables-save |grep -e mysql -e 192.168.4.191 -e &quot;-A KUBE-MARK-MASQ&quot; -e KUBE-SEP-HLHD6IM4G76NUUUM
  :KUBE-SEP-HLHD6IM4G76NUUUM - [0:0]
  -A KUBE-MARK-MASQ -j MARK --set-xmark 0x4000/0x4000
  -A KUBE-SEP-HLHD6IM4G76NUUUM -s 172.17.45.2/32 -m comment --comment &quot;enlighten/mysql:&quot; -j KUBE-MARK-MASQ
  -A KUBE-SEP-HLHD6IM4G76NUUUM -p tcp -m comment --comment &quot;enlighten/mysql:&quot; -m tcp -j DNAT --to-destination 172.17.45.2:3306
  -A KUBE-SERVICES -d 192.168.4.191/32 -p tcp -m comment --comment &quot;enlighten/mysql: cluster IP&quot; -m tcp --dport 3306 -j KUBE-SVC-FIZ3LEJD226YKZ4B
  -A KUBE-SVC-FIZ3LEJD226YKZ4B -m comment --comment &quot;enlighten/mysql:&quot; -j KUBE-SEP-HLHD6IM4G76NUUUM
  </code></pre>
  <p>Is it WAD or an issue?</p>