Regarding: http://nanog.org/meetings/nanog47/presentations/Wednesday/Hughes_Kosters_fundamentals_N47_Wed.pdf
Very common misconception for the "ipv6 enable" interface config
statement for IOS on slides 19, 21, etc.
The "ipv6 enable" statement is only necessary to enable IPv6 on an
interface if you are not assigning it an IPv6 address (e.g. this will
simply enable IPv6 with a LL address). Otherwise it is useless.
Would be a good idea to stop spreading the false assumption that "ipv6
enable" determines whether or not IPv6 is active on an interface.
Ray Soucy wrote:
Would be a good idea to stop spreading the false assumption that "ipv6
enable" determines whether or not IPv6 is active on an interface.
Play with IPv6 and is-is enough on a Cisco router, and you'll enable it as a matter of practice too. It's the definitive way to say "yes, this interface needs IPv6 active and I don't care if there's an address bound or not". I forget the exact circumstances, but I ran into several cases where I had undesired results and needed to manually enable IPv6 on an interface. Oh, and different versions of IOS behave differently towards IPv6. Imagine that.
Jack