Hi, Am 01.07.2011 um 13:41 schrieb Mikael Abrahamsson:
On Fri, 1 Jul 2011, Sascha Lenz wrote:
And why do you have gear that got no problem with an exploding IPv4 table after exhaustion, but can't cope with 20k IPv6 prefixes? I still don't get that. Please, someone finally explain to me why 20k or even 100k IPv6 Prefixes in the DFZ is a problem, my lab says, even my 5year old Ciscos and Junipers have no problems with that right now. The default for an old Sup720 is 500k IPv4 + 250k IPv6 prefixes or so for example (IIRC, was some time ago i tested that).
20k isn't a problem, 100k isn't really a problem, potentially 5M 30 years down the line might be a problem, 50M is most likely a problem.
You are in the IT business and you really think about 30+ years from now? Rather sounds like a science fiction author to me :-)
Right now the PI administration and implementation process is a barrier for entry, but if this changes then the amount of people who will want (and will get) PI might explode. Therefore the situation needs to be monitored, because having all core routers in the world keep track of every little entity who wants to redundantly connect to the Internet isn't going to scale.
This wasn't a real problem in the IPv4 world, i really doubt that is an immanent problem in the IPv6 world if the policies are identical; by design, most entities will have a single prefix (or per site worst case) and stay with that for most of their days. I'm not sure why there should be a higher IPv6 "PI" usage rate than for IPv4.
The real solution is to have end systems handle session handover between multiple addresses it has, but there seems to be pitifully little traction for that.
I think we've been there (sounds a bit like SHIM to me), we'll see if that takes on. But i don't think such workarounds can replace BGP multihoming in all cases. But it can help to spare some people the hassle to deal with full BGP multihoming if don't really need to be in the DFZ, but just want some level of redundancy indeed. -- Mit freundlichen Grüßen / Kind Regards Sascha Lenz [SLZ-RIPE] Senior System- & Network Architect