one of the benefits of having (and master) IPv6 is the fact, that it’s completely separate protocol from IPv4. please take a moment to think about it now. take special care about completely separate protocol. in case of doubt, read this again but slower. you can also make smart face or write it down and use next time you’re on some kind of C-level panel. practical effects on practical example this just happened, couple of hours ago....
one of the interesting and rarely seen configuration options, is ability to have redundant IPv6 tunnel established from source address tracked by HSRP. if you’re limited by other side of communication - in this example Hurricane Electric - to have only one endpoint of tunnel on your side that’s right tool for task. the way this configuration would work, is that router active in HSRP pair will be the one on which tunnel will be active and forwarding....
all memory and CPU related features in IPv6 world is major challenge even for modern hardware. unfortunately this is emphasized with lack of best practices followed by developers writing code. i just noticed there’s Microsoft Windows problem with IPv6 RA. it seems that actual problem is not limited only to RA, but actually - to the whole networking stack when working with link-local addresses. under Microsoft Windows code is allocating memory pretty recklessly....
everybody talks about IPv6 and still too few of us take it seriously. on polish mailing list dedicated to implementing IPv6 we get steady series of IPv6 prefix announcements, but real services available over this protocol is low. as a proof of concept for upcoming PLNOG, I just launched full network stack (Cisco 7200VXR with NPE-G1, ASA 5500-X, Catalyst 3750) and service (FreeBSD) for dual stack operation. IPv6 should be preferred, and while there’s still some things to tune down (like for example, DNS resolver in Windows XP), it should work....
there’s really almost nothing much simpler than starting to use IPv6. first of all, all major OS support IPv6 today. most of them are running it out of the box. second of all, tunnel brokers are available everywhere, so while i haven’t had luck with sixxs (they didn’t respond after weeks of waiting), using Hurricane Electric was easy and took like seconds. friendly “wizard” will walk you through and then even show example of configuration for your device....