Is a /48 still the smallest thing you can route independently?
I've finally convinced $DAYJOB to deploy IPv6. Justification for the IP space is easy, however the truth is that a /64 is more than we need in all locations. However the last I heard was that you can't effectively announce anything smaller than a /48. Is this still true? Is this likely to change in the immediate future, or do I need to ask for a /44? -- Jo Rhett Net Consonance : net philanthropy to improve open source and internet projects.
On 2012-10-11 23:02 , Jo Rhett wrote:
I've finally convinced $DAYJOB to deploy IPv6. Justification for the IP space is easy, however the truth is that a /64 is more than we need in all locations. However the last I heard was that you can't effectively announce anything smaller than a /48. Is this still true?
Is this likely to change in the immediate future, or do I need to ask for a /44?
A /64 is for a single link (broadcast domain, though with IPv6 multicast domain is more appropriate). A /48 (or /56 for end-users for some of the RIRs) is for a single end-site ("a different administrative domain and/or a different physical location"). If you thus have 5 end-sites, you should have room for 5 /48s and thus a /47 is what you can justify. If you though are not able to do transit / routing between those sites as they are not connected one might want to get separate PI /48s for them. But likely if you are in that camp, just asking for address space, that you can use stably for a long time, from your network provider who provides you connectivity is a better way to go. Greets, Jeroen
First:
But likely if you are in that camp, just asking for address space, that you can use stably for a long time, from your network provider who provides you connectivity is a better way to go.
Um, sorry I figured by the fact that I was posting on Nanog the context was clear, but I've forgotten how Nanog is now a go-to source for home network too :( The context was for what Nanog was originally intended for: We are provider-independent and peering around the world. On Oct 11, 2012, at 2:17 PM, Jeroen Massar wrote:
A /64 is for a single link …(snip)... A /48 (or /56 for end-users for some of the RIRs) is for a single end-site
Sorry, I wasn't looking for the breakdown of expected usage. I know those maps. What I was asking was whether you can PI-route a /56 or anything less than a /48 today. It's "nice" to have a few dozen of the entire Internet for each site, but totally unnecessary.
If you thus have 5 end-sites, you should have room for 5 /48s and thus a /47 is what you can justify.
Really? One bit can flip that many ways? ;-) I assume you mean /45, and apparently ARIN's recommended size is /44 anyway. -- Jo Rhett Net Consonance : net philanthropy to improve open source and internet projects.
On Oct 11, 2012, at 2:17 PM, Jeroen Massar <jeroen@unfix.org> wrote:
On 2012-10-11 23:02 , Jo Rhett wrote:
I've finally convinced $DAYJOB to deploy IPv6. Justification for the IP space is easy, however the truth is that a /64 is more than we need in all locations. However the last I heard was that you can't effectively announce anything smaller than a /48. Is this still true?
Is this likely to change in the immediate future, or do I need to ask for a /44?
A /64 is for a single link (broadcast domain, though with IPv6 multicast domain is more appropriate).
A /48 (or /56 for end-users for some of the RIRs) is for a single end-site ("a different administrative domain and/or a different physical location").
If you thus have 5 end-sites, you should have room for 5 /48s and thus a /47 is what you can justify.
Couple of errors there, Jeroen… 1. 5 /48s is at least a /45, not a /47 which is only 2 /48s. 2. Joe lives in the ARIN region where allocations and assignments are done on nibble boundaries, so his /45 would be rounded up to a /44 (as would a /47) anyway. Owen
On Thu, Oct 11, 2012 at 5:02 PM, Jo Rhett <jrhett@netconsonance.com> wrote:
I've finally convinced $DAYJOB to deploy IPv6. Justification for the IP space is easy, however the truth is that a /64 is more than we need in all locations. However the last I heard was that you can't effectively announce anything smaller than a /48. Is this still true?
Hi Jo, The short answer to your question is: /48 is the longest prefix from a direct RIR assignment that everyone currently accepts via BGP. /32 is the longest prefix from an ISP allocation that everyone currently accepts via BGP. As with IPv4 /24's, some folks accept longer prefixes. Not everyone.
Is this likely to change in the immediate future, or do I need to ask for a /44?
You need to ask for a /44. Regards, Bill Herrin -- William D. Herrin ................ herrin@dirtside.com bill@herrin.us 3005 Crane Dr. ...................... Web: <http://bill.herrin.us/> Falls Church, VA 22042-3004
one of the downsides to v6 is the huge amnt of space the folks expect you to announce. lots of space to do nefarious things. that said. if you select your peers carefully and don't mind a bit of hand crafting, you can /96 and even /112 that said, get a /32 and assign/announce /48s... /bill On Thu, Oct 11, 2012 at 02:02:17PM -0700, Jo Rhett wrote:
I've finally convinced $DAYJOB to deploy IPv6. Justification for the IP space is easy, however the truth is that a /64 is more than we need in all locations. However the last I heard was that you can't effectively announce anything smaller than a /48. Is this still true?
Is this likely to change in the immediate future, or do I need to ask for a /44?
-- Jo Rhett Net Consonance : net philanthropy to improve open source and internet projects.
Jo Rhett wrote:
I've finally convinced $DAYJOB to deploy IPv6. Justification for the IP space is easy, however the truth is that a /64 is more than we need in all locations. However the last I heard was that you can't effectively announce anything smaller than a /48. Is this still true?
Is this likely to change in the immediate future, or do I need to ask for a /44?
/48 is the new /24 randy
Subject: Re: Is a /48 still the smallest thing you can route independently? Date: Sat, Oct 13, 2012 at 09:01:51AM -1000 Quoting Randy Bush (randy@psg.com):
/48 is the new /24
Except you can stuff pretty much into one. I'm numbering my entire workplace from one. 1500 people and 26 offices. Our v4 is a constrained /16, which is enough. But not more. -- Måns Nilsson primary/secondary/besserwisser/machina MN-1334-RIPE +46 705 989668 FROZEN ENTREES may be flung by members of opposing SWANSON SECTS ...
RIPE Labs had an interesting article about filtering of /48 prefixes earlier this year that might be of some interest to you: https://labs.ripe.net/Members/emileaben/ripe-atlas-a-case-study-of-ipv6-48-f... There's also a useful RIPE Labs article on general prefix filtering lengths from August last year: https://labs.ripe.net/Members/dbayer/visibility-of-prefix-lengths Edward Dore Freethought Internet On 11 Oct 2012, at 22:02, Jo Rhett wrote:
I've finally convinced $DAYJOB to deploy IPv6. Justification for the IP space is easy, however the truth is that a /64 is more than we need in all locations. However the last I heard was that you can't effectively announce anything smaller than a /48. Is this still true?
Is this likely to change in the immediate future, or do I need to ask for a /44?
-- Jo Rhett Net Consonance : net philanthropy to improve open source and internet projects.
participants (8)
-
bmanning＠vacation.karoshi.com -
Edward Dore -
Jeroen Massar -
Jo Rhett -
Måns Nilsson -
Owen DeLong -
Randy Bush -
William Herrin