diff --git a/assets/u/image/k8s-v6-v4-dns.png b/assets/u/image/k8s-v6-v4-dns.png new file mode 100644 index 0000000..eab1caf Binary files /dev/null and b/assets/u/image/k8s-v6-v4-dns.png differ diff --git a/content/u/blog/kubernetes-making-dns-publicly-reachable/contents.lr b/content/u/blog/kubernetes-making-dns-publicly-reachable/contents.lr index ce32c8c..0970ed0 100644 --- a/content/u/blog/kubernetes-making-dns-publicly-reachable/contents.lr +++ b/content/u/blog/kubernetes-making-dns-publicly-reachable/contents.lr @@ -151,6 +151,33 @@ Keep-Alive: timeout=5 (attention, this is a test service and might not be running when you read this article at a later time) +## IPv6 vs. IPv4 + +Could we have achived the same with IPv4? The answere here is "maybe": +If the kubernetes service is reachable from globally reachable +nameservers via IPv4, then the answer is yes. This could be done via +public IPv4 addresses in the kubernetes cluster, via tunnels, VPNs, +etc. + +However, generally speaking, the DNS service of a +kubernetes cluster running on RFC1918 IP addresses, is probably not +reachable from globally reachable DNS servers by default. + +For IPv6 the case is a bit different: we are using globally reachable +IPv6 addresses in our k8s clusters, so they can potentially be +reachable without the need of any tunnel or whatsoever. Firewalling +and network policies can obviously prevent access, but if the IP +addresses are properly routed, they will be accessible from the public +Internet. + +And this makes things much easier for DNS servers, which are also +having IPv6 connectivity. + +The following pictures shows the practical difference between the two +approaches: + +![](/u/image/k8s-v6-v4-dns.png) + ## More of this We are discussing