Re: Is a /48 still the smallest thing you can route independently?
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-filtering 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.
Re: Is a /48 still the smallest thing you can route independently?
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
Re: Is a /48 still the smallest thing you can route independently?
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 (ra...@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 ... signature.asc Description: Digital signature
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.
Re: Is a /48 still the smallest thing you can route independently?
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
Re: Is a /48 still the smallest thing you can route independently?
--- jrh...@netconsonance.com wrote: From: Jo Rhett jrh...@netconsonance.com 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 /48 is 65536 /64s and a /44 is 16x65536 /64s. If you only need one subnet (1 subnet = 1 /64), why would you try to get 16x65536 subnets, rather than the 65536 you have in the /48? scott
Re: Is a /48 still the smallest thing you can route independently?
--- jrh...@netconsonance.com wrote: From: Jo Rhett jrh...@netconsonance.com 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 /48 is 65536 /64s and a /44 is 16x65536 /64s. If you only need one subnet (1 subnet = 1 /64), why would you try to get 16x65536 subnets, rather than the 65536 you have in the /48? scott He said it was for multiple sites. Per ARIN policy, the next biggest chunk from a /48 is a /44, so a /44 is what should be asked for. It is perfectly justifiable if you have more than 1 site. I would not expect anything smaller than a /48 to be allowed in BGP. A bonus would be that a /44 currently costs the same as a /48 for an enduser, so there really is no drawback from getting the /44, and having enough space to not have to worry about it in the future. -Randy
Re: Is a /48 still the smallest thing you can route independently?
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.
Re: Is a /48 still the smallest thing you can route independently?
On Oct 11, 2012, at 2:28 PM, Randy Carpenter wrote: so there really is no drawback from getting the /44, and having enough space to not have to worry about it in the future. It's only a worry if you can only route /48s, which was my question. And seriously, we're going to be banging around in the emptiness as compared to our IPv4 allocations. :) -- Jo Rhett Net Consonance : net philanthropy to improve open source and internet projects.
Re: Is a /48 still the smallest thing you can route independently?
On Thu, Oct 11, 2012 at 5:02 PM, Jo Rhett jrh...@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 her...@dirtside.com b...@herrin.us 3005 Crane Dr. .. Web: http://bill.herrin.us/ Falls Church, VA 22042-3004
Re: Is a /48 still the smallest thing you can route independently?
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.
Re: Is a /48 still the smallest thing you can route independently?
--- rcar...@network1.net wrote: From: Randy Carpenter rcar...@network1.net --- jrh...@netconsonance.com wrote: From: Jo Rhett jrh...@netconsonance.com 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 /48 is 65536 /64s and a /44 is 16x65536 /64s. If you only need one subnet (1 subnet = 1 /64), why would you try to get 16x65536 subnets, rather than the 65536 you have in the /48? --- He said it was for multiple sites. --- DOH! Note to self: focus on the outage and don't respond to NANOG while troubleshooting. ;-) scott
Re: Is a /48 still the smallest thing you can route independently?
- Original Message - On Oct 11, 2012, at 2:28 PM, Randy Carpenter wrote: so there really is no drawback from getting the /44, and having enough space to not have to worry about it in the future. It's only a worry if you can only route /48s, which was my question. And seriously, we're going to be banging around in the emptiness as compared to our IPv4 allocations. :) You can route /48 or shorter (larger) How many sites do you have? If less than 192, /44 is perfect, unless some of those sites require more than a /48. Then, it gets more complicated :-) -Randy
Re: Is a /48 still the smallest thing you can route independently?
On Thu, Oct 11, 2012 at 6:06 PM, Randy Carpenter rcar...@network1.net wrote: How many sites do you have? If less than 192, /44 is perfect, unless some of those sites require more than a /48. Then, it gets more complicated :-) We're having a general math breakdown today. First Jeroen wants to fit 5 /48's in a /47 and now you want to fit 192 /48's in a /44. 48-44=4. 2^4=16. -Bill -- William D. Herrin her...@dirtside.com b...@herrin.us 3005 Crane Dr. .. Web: http://bill.herrin.us/ Falls Church, VA 22042-3004
Re: Is a /48 still the smallest thing you can route independently?
Wow and I thought nibble boundaries would make the math easier than HD ratios. Here's the breakdown for those who are mathematically challenged: n sites prefix 0 Nothing. 1 /48 2-12/44 13-191 /40 192-3071/36 3072-49,151 /32 49,152-786,431 /28 If you're managing more than 786,431 sites, then you should be able to afford to hire someone who can properly handle the math. Owen
Re: Is a /48 still the smallest thing you can route independently?
- Original Message - On Thu, Oct 11, 2012 at 6:06 PM, Randy Carpenter rcar...@network1.net wrote: How many sites do you have? If less than 192, /44 is perfect, unless some of those sites require more than a /48. Then, it gets more complicated :-) We're having a general math breakdown today. First Jeroen wants to fit 5 /48's in a /47 and now you want to fit 192 /48's in a /44. 48-44=4. 2^4=16. -Bill Yep... I don't know why, but I was thinking /40. So, 1 site = /48 2-12 sites = /44 13-192 sites = /40, and so on. NRPM 6.5.8.2 for details. /40 bumps you into the next price category, but it is a 1-time expense for endusers. -Randy
Re: Is a /48 still the smallest thing you can route independently?
On 10/11/12, William Herrin b...@herrin.us wrote: On Thu, Oct 11, 2012 at 6:06 PM, Randy Carpenter rcar...@network1.net wrote: How many sites do you have? If less than 192, /44 is perfect, unless some of those sites require more than a /48. Then, it gets more complicated :-) We're having a general math breakdown today. First Jeroen wants to fit 5 /48's in a /47 and now you want to fit 192 /48's in a /44. 48-44=4. 2^4=16. Right, last I checked the smallest integer = Log base 2 of 5 is not less than or equal to 1, therefore, you will never fit 5 /48s in the network just by subtracting 1 from the prefix length. if you want a prefix /yy that will accommodate a certain number N of /xx Then you must ensure that 2^(xx - yy) = N not 5^(xx -yy ) = N -Bill -- -J
