IPv6 Cache Servers + IPv4 Forwarders
Our company has implemented an native IPv6 link and we now have an IPv6 only network. However, on testing through test-ipv6.com, the score for IPv6 stability and readiness was just 7/10. The problem is that the two DNS resolvers riding on IPv6 offered by the serving ISP are just caching servers which pass queries to two forwarders. The forwarders can only support IPv4. We are surprised to note that an IPv6 capable ISP does not offer full IPv6 connectivity to its name resolving systems. This will affect our global IPv6 reachability.
As a small customer, we do not have the power to ask the ISP to change its network architecture. We can only just alert the ISP hoping that it will do something positive. On the other hand, the cost of setting up our own IPv6 or dual-stack resolvers is insignificant.