Kubernetes networking and the outside world

a story about how K8S chats with its friends

Laurent CORBES (Enix) (@lcaflc)

Who's ENIX?

A team of experts who can help you with:
  • Container Orchestration
    (consulting, training, managed Kubernetes hosting)
  • Network
    (our teams have built CDNs and dark fiber networks)
  • Virtualization
    (we were already selling Xen VMs in 2005)
  • Hosting
    (let's Terraform your OpenStack)


  • K8S networking model
  • Custom Integration
  • Kube-Router

K8S networking model

  • direct containers and nodes communication
  • Containers see their own IP
  • IP per Pod
  • Cluster network
Pod to Pod network communication:

On all setups there is an "easy" solution.

External network communication:
  • Inbound: External to K8s Services
  • Outbound: Pods to external
  • External to Pods (Why not !)



  • SNAT
  • Routing
  • CNI integration

Standard modules not sufficient

Need some extra integration

Super Glue

Cloud Providers world
  • K8s as a Service
  • CNI driver
  • Services load balancer
On Premise subworld



The Clone Wars

  • Integration standard
  • Neutron LBaaS
  • Layer2 networking

Self made Load Balancer

No Pain, No Gain

  • Time consuming
  • Simple load balancer + NodePort
  • Dynamic with K8s API
  • Ingress Controller


Old pipes give sweetest smoke


Pod to Pod networking
  • Fully Dynamic
  • Fully meshed
  • No NAT
  • Network Policy
  • Dynamic Loadbalancing
  • L4 TCP/UDP
  • DSR support
BGP advertisement
  • Any BGP router support
  • Cluster network and pod CIDRs
  • Services ClusterIP / External IP
  • ECMP

This is the End

  • On cloud is easy
  • But on premise is possible

Formation Kubernetes

Enix propose une formation Déployer ses applications avec Kubernetes.

17/18 et 20/21 septembre 2018 à Paris

Contact: formation@enix.io