Our internal network and internal services are IPv6-enabled, and we're considering enabling IPv6 on public-facing SMTP, DNS and Web servers. All the guides / whitepapers I've read on the subject speak only about the benefits, but I'm sure there are also some downsides. For example:
- Clients with IPv6 via tunnels will have slower access to our services if we enable IPv6.
- Clients with broken IPv6 won't be able to access them at all.
Given that only very small percentage of users have working IPv6, and those that do are usually dual-stack, I'm inclined to think that enabling IPv6 when you don't control both sides of the communication channel is actually a bad idea in 2011.
Is there any research / papers / articles on this subject?