PLCs support of IPv6 address space & features

What is the status of IPv6 support in PLCs? A large number of PLCs have IP comm stacks that support IPv4. With the transition (probably will take many years) to IPv6 as we replace or upgrade PLCs we'd like to consider being IPv6 compliant.

Are you aware of vendors that are IPv6 compliant?

Thanks!

Why does it matter?

Are your PLCs accesible through the internet? Hopefully not without a router.

PLCs and IPv6 Support

In general, our goal is to implement IPv6 compatible devices throughout our systems. IPv6 provides support for true end-to-end security with IPsec, eliminates the need for NAT, and QoS functions may be beneficial, if not now possibly in the future. New applications in our control systems may benefit from peer-to-peer comms which is better supported in IPv6. If we need to replace an RTU, it seems to make sense to go with an IPv6 compatible device.

Our PLCs are not directly accesible via the Internet.

Comments please.