[149423] in North American Network Operators' Group
Re: IPv6 dual stacking and route tables
daemon@ATHENA.MIT.EDU (Jeroen Massar)
Fri Feb 3 15:48:01 2012
Date: Fri, 03 Feb 2012 21:47:00 +0100
From: Jeroen Massar <jeroen@unfix.org>
To: -Hammer- <bhmccie@gmail.com>
In-Reply-To: <4F2C4598.5060505@gmail.com>
Cc: nanog@nanog.org
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On 2012-02-03 21:37 , -Hammer- wrote:
> Thanks Jeroen (and Ryan/Philip/Cameron/Justin/Etc.) for all the online
> and offline responses. That was fast. The struggle is that I'm having
> trouble seeing how/why it would matter other than potential latency on
> the IPv4 side. IPv6 conversations usually involve taking the full table
> when dealing with multi-homed/multi-site setups. IPv4 I didn't really
> consider (taking the full table) until I mentioned this to some of my
> vendors technical folks and it caused a lot of reflection. Not on the L3
> part. Just on the DNS part. This appears to be a tough subject area when
> it comes to V4/V6 deployment strategies. The bottom line is that I'll
> take whatever the carrier feeds in V6. Just trying to see where I would
> be missing out by not doing the same in V4. Again, I have the hardware
> to support it and I really have no reason not to do it. I just want to
> be able to justify to myself why I'm doing it.
Why you want non-defaults in both IPv4 and IPv6:
- more possible paths
- less chances of blackholes.
And of course, those paths will be more stable and you don't get
hot-potato swapping between two defaults.
And that in turn allows the Happy Eyeballs mechanisms to do their jobs
much better as they keep a history per host or prefix, they assume IPv6
/48's and IPv4 /24's from what I have seen, in some cases.
Greets,
Jeroen
