I had one-off experience recently: tried to add IPv6 CIDR for accessing k8s master, and FE validated it perfectly but somewhere on BE they validated it with reg

I had one-off experience recently: tried to add IPv6 CIDR for accessing k8s master, and FE validated it perfectly but somewhere on BE they validated it with regexp that accepted only IPv4 CIDRs, but at least up to 999.999.999.999/99, so not that bad. /s