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not able to ping or reach cluster ip or cluster/service FQDN from any pod in same namespce

abidahmeds
abidahmeds Posts: 2
in LFS258 Class Forum

i dont know if i am only facing this problem , i dont see a option of giving a hostname and using FQDN to reach Pod/cluster. although if i use Pod IP , i can reach the Pod /containers.
i think it is due to kube proxy not working properly in my setup , i dont see any iptables-save output . Does anyonw know if this is a setup issue , i ammusing ubuntu and installing kube-adm as per lab document. my pod-cidr is completely different network from the cluster-cidr ( whihc i think comes default since no step was given in lab document) . since they are different , a Ip route from kube proxy is required but with no tables, obviously service FQDN never works.
who can help please, if you face same problem ??

Comments

  • chrispokorni
    chrispokorni Posts: 2,605

    Hi,
    Can you post a snippet of the command you are running and the error output? It may help in troubleshooting the issue.
    Ideally, pods should be able to communicate with each other once calico is installed. Containers can communicate with each other via localhost.
    Details of the Kubernetes networking model can be found below:
    https://kubernetes.io/docs/concepts/cluster-administration/networking/

    Regards,
    -Chris

  • abidahmeds
    abidahmeds Posts: 2

    it is more within cluster networking and not external . Pod to Pod communication using cluster IP or FQDN for the service. I saw lot of comments in web regarding setting hairpin- veth in Kubelet config , to check if Kube proxy running properly .. I used standard setup given in lab document Kube adm, Kubectl, Kubelet 1.11.1-00 on ubuntu and applied calico. not sure whihc step i missed , may be i need to resinstall and check again. But i find it strange that reaching other poD using cluster IP/FQDN is not working , where as using PoD IP , it does. so i think it is about routing btw PoDs , possibly even DNS entries ( for FQDN ) .
    will check and install again , and add more information here if i face same problem.

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