instruction: Create a Dockerfile for networking
output: ```dockerfile
  from one of your Nodes:curl 10.0.1.175:80
  hostnames-632524106-bbpiw
  If this still fails, look at the kube-proxy logs for specific lines like:Setting endpoints for default/hostnames:default to [10.244.0.5:9376 10.244.0.6:9376 10.244.0.7:9376]
  If you don't see those, try restarting kube-proxy with the -v flag set to 4, and
  then look at the logs again.Edge case: A Pod fails to reach itself via the Service IPThis might sound unlikely, but it does happen and it is supposed to work.This can happen when the network is not properly configured for "hairpin"
  traffic, usually when kube-proxy is running in iptables mode and Pods
  are connected with bridge network. The Kubelet exposes a hairpin-mode
  flag that allows endpoints of a Service to loadbalance
  back to themselves if they try to access their own Service VIP. The
  hairpin-mode flag must either be set to hairpin-veth or
  promiscuous-bridge.The common steps to trouble shoot this are as follows:Confirm hairpin-mode is set to hairpin-veth or promiscuous-bridge.
  You should see something like the below. hairpin-mode is set to
  promiscuous-bridge in the following example.ps auxw | grep kubelet
  root 3392 1.1 0.8 186804 65208 ? Sl 00:51 11:11 /usr/local/bin/kubelet --enable-debugging-handlers=true --config=/etc/kubernetes/manifests --allow-privileged=True --v=4 --cluster-dns=10.0.0.10 --cluster-domain=cluster.local --configure-cbr0=true --cgroup-root=/ --system-cgroups=/system --hairpin-mode=promiscuous-bridge --runtime-cgroups=/docker-daemon --kubelet-cgroups=/kubelet --babysit-daemons=true --max-pods=110 --serialize-image-pulls=false --outofdisk-transition-frequency=0
  Confirm the effective hairpin-mode. To do this, you'll have to look at
  kubelet log. Accessing the logs depends on your Node OS. On some OSes it
  is a file, such as /var/log/kubelet.log, while other OSes use journalctl
  to access logs. Please be noted that the effective hairpin mode may not
  match --hairpin-mode flag due to compatibility. Check if there is any log
  lines with key word hairpin in kubelet.log. There should be log lines
  indicating the effective hairpin mode, like something below.I0629 00:51:43.648698 3252 kubelet.go:380] Hairpin mode set to "promiscuous-bridge"
  If the effective hairpin mode is hairpin-veth, ensure the Kubelet has
  the permission to operate in /sys on node. If everything works properly,
  you should see something like:for intf in /sys/devices/virtual/net/cbr0/brif/*; do cat $intf/hairpin_mode; done
  1
  1
  1
  1
  If the effective hairpin mode is promiscuous-bridge, ensure Kubelet
  has the permission to manipulate linux bridge on node. If cbr0 bridge is
  used and configured properly, you should see:ifconfig cbr0 |grep PROMISC
  UP BROADCAST RUNNING PROMISC MULTICAST MTU:1460 Metric:1
  Seek help if none of above works out.Seek helpIf you get this far, something very strange is happening. Your Service is
  running, has EndpointSlices, and your Pods are actually serving. You have DNS
  working, and kube-proxy does not seem to be misbehaving. And yet your
  Service is not working. Please let us know what is going on, so we can help
  investigate!Contact us on
  Slack or
  Forum or
  GitHub.What's nextVisit the troubleshooting overview document
  for more information.FeedbackWas this page helpful?Yes
  NoThanks for the feedback. If you have a specific, answerable question about how to use Kubernetes, ask it on
  Stack Overflow.
  Open an issue in the GitHub Repository if you want to
  report a problem
  or
  suggest an improvement.Last modified April 09, 2025 at 5:08 AM PST: Update docs for deprecation of Endpoints API (#49831) (649bda2cbd)  Create child page
   Create an issue
   Print entire sectionRunning commands in a PodSetupDoes the Service exist?Any Network Policy Ingress rules affecting the target Pods?Does the Service work by DNS name?Does any Service work by DNS name?Does the Service work by IP?Is the Service defined correctly?Does the Service have any EndpointSlices?Are the Pods working?Is the kube-proxy working?Is kube-proxy running?Is kube-proxy proxying?Edge case: A Pod fails to reach itself via the Service IPSeek helpWhat's next© 2025 The Kubernetes Authors | Documentation Distributed under CC BY 4.0© 2025 The Linux Foundation ®. ```