Greetings NANOG, I've always been under the impression its best practice to only announce prefixes of a /24 and above when it comes to IPv4 and BGP. I was wondering if something similar had been agreed upon regarding IPv6. And if That's the case, What's the magic number? /32? /48? /64? Nick Olsen Network Operations (855) FLSPEED x106
On Tue, 26 Apr 2011, Nick Olsen wrote:
I've always been under the impression its best practice to only announce prefixes of a /24 and above when it comes to IPv4 and BGP. I was wondering if something similar had been agreed upon regarding IPv6. And if That's the case, What's the magic number? /32? /48? /64?
You're likely to get different answers to this, but the 'magic number' appears to be /48. Looking in the v6 BGP table, you will likely find smaller prefixes than that, but a number of the major carriers seem to be settling on /48 as the smallest prefix they will accept. /48 is also the smallest block most of the RIRs will assign to end-users. jms
Funny enough, some carriers actually require the 'smallest' as being /32... :( -----Original Message----- From: Justin M. Streiner [mailto:streiner@cluebyfour.org] Sent: Tuesday, April 26, 2011 9:34 AM To: nanog@nanog.org Subject: Re: IPv6 Prefix announcing On Tue, 26 Apr 2011, Nick Olsen wrote:
I've always been under the impression its best practice to only announce prefixes of a /24 and above when it comes to IPv4 and BGP. I was wondering if something similar had been agreed upon regarding IPv6. And if That's the case, What's the magic number? /32? /48? /64?
You're likely to get different answers to this, but the 'magic number' appears to be /48. Looking in the v6 BGP table, you will likely find smaller prefixes than that, but a number of the major carriers seem to be settling on /48 as the smallest prefix they will accept. /48 is also the smallest block most of the RIRs will assign to end-users. jms
On Apr 26, 2011, at 12:39 PM, Kate Gerry wrote:
Funny enough, some carriers actually require the 'smallest' as being /32... :(
Vote with your wallet. Some carriers would prefer if only transit free networks were allowed to originate routes. Doesn't mean you should follow their lead. -- TTFN, patrick
-----Original Message----- From: Justin M. Streiner [mailto:streiner@cluebyfour.org] Sent: Tuesday, April 26, 2011 9:34 AM To: nanog@nanog.org Subject: Re: IPv6 Prefix announcing
On Tue, 26 Apr 2011, Nick Olsen wrote:
I've always been under the impression its best practice to only announce prefixes of a /24 and above when it comes to IPv4 and BGP. I was wondering if something similar had been agreed upon regarding IPv6. And if That's the case, What's the magic number? /32? /48? /64?
You're likely to get different answers to this, but the 'magic number' appears to be /48. Looking in the v6 BGP table, you will likely find smaller prefixes than that, but a number of the major carriers seem to be settling on /48 as the smallest prefix they will accept. /48 is also the smallest block most of the RIRs will assign to end-users.
jms
From: Kate Gerry Sent: Tuesday, April 26, 2011 9:39 AM To: 'Justin M. Streiner'; nanog@nanog.org Subject: RE: IPv6 Prefix announcing
Funny enough, some carriers actually require the 'smallest' as being /32... :(
That might be true in PA space, but PI space is issued down to /48. I am not aware of anyone who filters smaller than a /32 in PI space though that doesn't mean it doesn't happen. The largest holdout was Verizon but my understanding is they now accept a /48 in PI space. So: A /32 is the smallest prefix issued in PA and some networks will not accept a prefix smaller than /32 from PA address space. A /48 is the smallest prefix issued in PI and some networks will not accept a prefix smaller than /48 from PI address space. In other words, if you are going to attempt to multihome a /48 allocation from your provider's aggregate, you are better off getting your own provider independent block.
I know that used to be true, but, to the best of my knowledge, everyone is now accepting down to /48s in provider independent ranges. Some still require /32 or shorter in the provider aggregate ranges. Owen Sent from my iPad On Apr 26, 2011, at 10:39 AM, Kate Gerry <kate@quadranet.com> wrote:
Funny enough, some carriers actually require the 'smallest' as being /32... :(
-----Original Message----- From: Justin M. Streiner [mailto:streiner@cluebyfour.org] Sent: Tuesday, April 26, 2011 9:34 AM To: nanog@nanog.org Subject: Re: IPv6 Prefix announcing
On Tue, 26 Apr 2011, Nick Olsen wrote:
I've always been under the impression its best practice to only announce prefixes of a /24 and above when it comes to IPv4 and BGP. I was wondering if something similar had been agreed upon regarding IPv6. And if That's the case, What's the magic number? /32? /48? /64?
You're likely to get different answers to this, but the 'magic number' appears to be /48. Looking in the v6 BGP table, you will likely find smaller prefixes than that, but a number of the major carriers seem to be settling on /48 as the smallest prefix they will accept. /48 is also the smallest block most of the RIRs will assign to end-users.
jms
On 4/26/2011 09:39, Kate Gerry wrote:
Funny enough, some carriers actually require the 'smallest' as being /32... :(
This is becoming the exception now, not the rule. Last year I was fighting with Verizon about their refusal to carry /48s. That, together with the impasse of figuring out how to put dual stack IPv6 on an Ethernet port (it was delivered as IPv4 only multiple times), I never accepted it and went with a competitor who got it right the first time. However, I've had several sources tell me Verizon has since backpedaled and now accepts /48s. ~Seth
-----Original Message----- From: Seth Mattinen [mailto:sethm@rollernet.us] Sent: Tuesday, April 26, 2011 12:52 PM To: nanog@nanog.org Subject: Re: IPv6 Prefix announcing
On 4/26/2011 09:39, Kate Gerry wrote:
Funny enough, some carriers actually require the 'smallest' as being /32... :(
This is becoming the exception now, not the rule.
Last year I was fighting with Verizon about their refusal to carry /48s. That, together with the impasse of figuring out how to put dual stack IPv6 on an Ethernet port (it was delivered as IPv4 only multiple times), I never accepted it and went with a competitor who got it right the first time. However, I've had several sources tell me Verizon has since backpedaled and now accepts /48s.
~Seth
*> 2001:67C:120::/48 2001:504:16::1B1B 150 0 6939 701 12702 43751 6716 i Mike
On Tue, Apr 26, 2011 at 12:30 PM, Nick Olsen <nick@flhsi.com> wrote:
Greetings NANOG, I've always been under the impression its best practice to only announce prefixes of a /24 and above when it comes to IPv4 and BGP. I was wondering if something similar had been agreed upon regarding IPv6. And if That's the case, What's the magic number? /32? /48? /64?
Hi Nick, At this point, you can depend on being able to announce a /32 from any block and a /48 from an RIR block designated for end-user assignments. Many carriers have more permissive policies but all of any consequence now allow at least that. 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
participants (9)
-
George Bonser -
Justin M. Streiner -
Kate Gerry -
Michael K. Smith - Adhost -
Nick Olsen -
Owen DeLong -
Patrick W. Gilmore -
Seth Mattinen -
William Herrin