Re: IPv6 /48 advertisements

2013-12-18 Thread Chuck Anderson
On Wed, Dec 18, 2013 at 09:11:46AM -0700, Cliff Bowles wrote: 
 Question: will carriers accept IPv6 advertisements smaller than /48?

Not generally, no.

 Our org was approved a /36 based on number of locations. The bulk of
 those IPs will be in the data centers. As we were chopping up the
 address space, it was determined that the remote campus locations
 would be fine with a /60 per site. (16 networks of /64). There are
 usually less than 50 people at the majority of these locations and
 only about 10 different functional VLANs (Voice, Data, Local
 Services, Wireless, Guest Wireless, etc...).

 Now, there has been talk about putting an internet link in every
 campus rather than back hauling it all to the data centers via
 MPLS. However, if we do this, then would we need a /48 per campus?
 That is massively wasteful, at 65,536 networks per location.  Is the
 /48 requirement set in stone? Will any carriers consider longer
 prefixes?

/48 per site is the standard.

 I know some people are always saying that the old mentality of
 conserving space needs to go away, but I was bitten by that IPv4
 issue back in the day and have done a few VLSM network
 overhauls. I'd rather not massively allocate unless it's a
 requirement.

You need to throw out all old thinking in terms of what happened in
IPv4.  Current ARIN policy allows a /48 per site and that is how you
should architect the network.



Re: IPv6 /48 advertisements

2013-12-18 Thread Edward Dore
If you’re talking about announcing each location separately, then RIPE have a 
couple of useful articles about prefix visibility on Ripe Labs:

https://labs.ripe.net/Members/emileaben/ripe-atlas-a-case-study-of-ipv6-48-filtering
https://labs.ripe.net/Members/dbayer/visibility-of-prefix-lengths

Otherwise I guess you’ll need to talk to your chosen carrier(s) about 
aggregating your space for you, which will come down to their policies on what 
routes they will carry internally.

Edward Dore 
Freethought Internet 

On 18 Dec 2013, at 16:11, Cliff Bowles cliff.bow...@apollogrp.edu wrote:

 I accidentally sent this to nanog-request yesterday. I could use some 
 feedback from anyone that can help, please.
 
 Question: will carriers accept IPv6 advertisements smaller than /48?
 
 Our org was approved a /36 based on number of locations. The bulk of those 
 IPs will be in the data centers. As we were chopping up the address space, it 
 was determined that the remote campus locations would be fine with a /60 per 
 site. (16 networks of /64). There are usually less than 50 people at the 
 majority of these locations and only about 10 different functional VLANs 
 (Voice, Data, Local Services, Wireless, Guest Wireless, etc...).
 
 Now, there has been talk about putting an internet link in every campus 
 rather than back hauling it all to the data centers via MPLS. However, if we 
 do this, then would we need a /48 per campus? That is massively wasteful, at 
 65,536 networks per location.  Is the /48 requirement set in stone? Will any 
 carriers consider longer prefixes?
 
 I know some people are always saying that the old mentality of conserving 
 space needs to go away, but I was bitten by that IPv4 issue back in the day 
 and have done a few VLSM network overhauls. I'd rather not massively allocate 
 unless it's a requirement.
 
 Thanks in advance.
 
 CWB
 
 
 
 
 
 This message is private and confidential. If you have received it in error, 
 please notify the sender and remove it from your system.
 



Re: IPv6 /48 advertisements

2013-12-18 Thread Blake Dunlap
Regardless of the carriers, you'll find most ASs on the internet only
listen to /48 or larger. So even if you get your prefixes accepted by your
provider, don't assume you can get anywhere, or have your packets not fall
in to uRPF blackholes randomly without a larger aggregate announcement.

-Blake


On Wed, Dec 18, 2013 at 10:22 AM, Edward Dore 
edward.d...@freethought-internet.co.uk wrote:

 If you’re talking about announcing each location separately, then RIPE
 have a couple of useful articles about prefix visibility on Ripe Labs:


 https://labs.ripe.net/Members/emileaben/ripe-atlas-a-case-study-of-ipv6-48-filtering
 https://labs.ripe.net/Members/dbayer/visibility-of-prefix-lengths

 Otherwise I guess you’ll need to talk to your chosen carrier(s) about
 aggregating your space for you, which will come down to their policies on
 what routes they will carry internally.

 Edward Dore
 Freethought Internet

 On 18 Dec 2013, at 16:11, Cliff Bowles cliff.bow...@apollogrp.edu wrote:

  I accidentally sent this to nanog-request yesterday. I could use some
 feedback from anyone that can help, please.
 
  Question: will carriers accept IPv6 advertisements smaller than /48?
 
  Our org was approved a /36 based on number of locations. The bulk of
 those IPs will be in the data centers. As we were chopping up the address
 space, it was determined that the remote campus locations would be fine
 with a /60 per site. (16 networks of /64). There are usually less than 50
 people at the majority of these locations and only about 10 different
 functional VLANs (Voice, Data, Local Services, Wireless, Guest Wireless,
 etc...).
 
  Now, there has been talk about putting an internet link in every campus
 rather than back hauling it all to the data centers via MPLS. However, if
 we do this, then would we need a /48 per campus? That is massively
 wasteful, at 65,536 networks per location.  Is the /48 requirement set in
 stone? Will any carriers consider longer prefixes?
 
  I know some people are always saying that the old mentality of
 conserving space needs to go away, but I was bitten by that IPv4 issue back
 in the day and have done a few VLSM network overhauls. I'd rather not
 massively allocate unless it's a requirement.
 
  Thanks in advance.
 
  CWB
 
 
 
 
  
  This message is private and confidential. If you have received it in
 error, please notify the sender and remove it from your system.
 




Re: IPv6 /48 advertisements

2013-12-18 Thread Laszlo Hanyecz
It's standard to filter out anything longer than /48.

Your /36 prefix was chosen based on the number of sites, with a /48 per site, 
so just keep it simple.  Trying to manage it in the way IPv4 addresses were 
managed will just ensure that you will have the same headaches of micro 
managing sub allocations and trying to guess the right sizes.  The address 
space in V6 is large enough that you don't have to spend your time worrying 
about this, and that's one of the reasons for using a /48 at each site.

Think of an IPv6 /48 like you would think of an IPv4 /24 - except that it's the 
right size for either your house or your university campus.

Laszlo


On Dec 18, 2013, at 4:11 PM, Cliff Bowles cliff.bow...@apollogrp.edu wrote:

 I accidentally sent this to nanog-request yesterday. I could use some 
 feedback from anyone that can help, please.
 
 Question: will carriers accept IPv6 advertisements smaller than /48?
 
 Our org was approved a /36 based on number of locations. The bulk of those 
 IPs will be in the data centers. As we were chopping up the address space, it 
 was determined that the remote campus locations would be fine with a /60 per 
 site. (16 networks of /64). There are usually less than 50 people at the 
 majority of these locations and only about 10 different functional VLANs 
 (Voice, Data, Local Services, Wireless, Guest Wireless, etc...).
 
 Now, there has been talk about putting an internet link in every campus 
 rather than back hauling it all to the data centers via MPLS. However, if we 
 do this, then would we need a /48 per campus? That is massively wasteful, at 
 65,536 networks per location.  Is the /48 requirement set in stone? Will any 
 carriers consider longer prefixes?
 
 I know some people are always saying that the old mentality of conserving 
 space needs to go away, but I was bitten by that IPv4 issue back in the day 
 and have done a few VLSM network overhauls. I'd rather not massively allocate 
 unless it's a requirement.
 
 Thanks in advance.
 
 CWB
 
 
 
 
 
 This message is private and confidential. If you have received it in error, 
 please notify the sender and remove it from your system.
 




Re: IPv6 /48 advertisements

2013-12-18 Thread Justin M. Streiner

On Wed, 18 Dec 2013, Cliff Bowles wrote:


Question: will carriers accept IPv6 advertisements smaller than /48?


Most of the carriers I've seen won't accept anything smaller than /48. 
You have 4096 /48s to use in your /36.  The bigger concern for carriers/ISPs

is IPv6 routing table bloat from carrying lots of small individual
advertisements.

jms



RE: IPv6 /48 advertisements

2013-12-18 Thread Cliff Bowles
I had a feeling... thanks for the feedback.

CWB

From: Blake Dunlap [mailto:iki...@gmail.com]
Sent: Wednesday, December 18, 2013 9:32 AM
To: Edward Dore
Cc: Cliff Bowles; nanog@nanog.org
Subject: Re: IPv6 /48 advertisements

Regardless of the carriers, you'll find most ASs on the internet only listen to 
/48 or larger. So even if you get your prefixes accepted by your provider, 
don't assume you can get anywhere, or have your packets not fall in to uRPF 
blackholes randomly without a larger aggregate announcement.
-Blake

On Wed, Dec 18, 2013 at 10:22 AM, Edward Dore 
edward.d...@freethought-internet.co.ukmailto:edward.d...@freethought-internet.co.uk
 wrote:
If you're talking about announcing each location separately, then RIPE have a 
couple of useful articles about prefix visibility on Ripe Labs:

https://labs.ripe.net/Members/emileaben/ripe-atlas-a-case-study-of-ipv6-48-filtering
https://labs.ripe.net/Members/dbayer/visibility-of-prefix-lengths

Otherwise I guess you'll need to talk to your chosen carrier(s) about 
aggregating your space for you, which will come down to their policies on what 
routes they will carry internally.

Edward Dore
Freethought Internet

On 18 Dec 2013, at 16:11, Cliff Bowles 
cliff.bow...@apollogrp.edumailto:cliff.bow...@apollogrp.edu wrote:

 I accidentally sent this to nanog-request yesterday. I could use some 
 feedback from anyone that can help, please.

 Question: will carriers accept IPv6 advertisements smaller than /48?

 Our org was approved a /36 based on number of locations. The bulk of those 
 IPs will be in the data centers. As we were chopping up the address space, it 
 was determined that the remote campus locations would be fine with a /60 per 
 site. (16 networks of /64). There are usually less than 50 people at the 
 majority of these locations and only about 10 different functional VLANs 
 (Voice, Data, Local Services, Wireless, Guest Wireless, etc...).

 Now, there has been talk about putting an internet link in every campus 
 rather than back hauling it all to the data centers via MPLS. However, if we 
 do this, then would we need a /48 per campus? That is massively wasteful, at 
 65,536 networks per location.  Is the /48 requirement set in stone? Will any 
 carriers consider longer prefixes?

 I know some people are always saying that the old mentality of conserving 
 space needs to go away, but I was bitten by that IPv4 issue back in the day 
 and have done a few VLSM network overhauls. I'd rather not massively allocate 
 unless it's a requirement.

 Thanks in advance.

 CWB




 
 This message is private and confidential. If you have received it in error, 
 please notify the sender and remove it from your system.




This message is private and confidential. If you have received it in error, 
please notify the sender and remove it from your system.



Re: IPv6 /48 advertisements

2013-12-18 Thread Jeroen Massar
On 2013-12-18 17:11 , Cliff Bowles wrote:
 I accidentally sent this to nanog-request yesterday. I could use some 
 feedback from anyone that can help, please.
 
 Question: will carriers accept IPv6 advertisements smaller than /48?
 
 Our org was approved a /36 based on number of locations.

In GRH (http://www.sixxs.net/tools/grh/) I only see 2620:0:5030::/48,
thus did you get another/new/updated one very recently?

Note that there are quite a few ISPs who filter on the assigned prefix
length, especially for PA address space which should be Aggregated by
the Provider (PA).

Likely your space comes out of one of the PI blocks, in which case rules
tend to be a bit more lax, hence a /48 should get through.

Do note that at one point or another there will be ISPs/networks that
are going to hit their prefix table sizes on their hardware. These will
start filtering aggressively on the assigned prefixes.

Greets,
 Jeroen




Re: IPv6 /48 advertisements

2013-12-18 Thread Antonio M. Moreiras
What do you recommend to an end user that have a direct assignment of a
/48, and would like to disaggregate as part of a traffic engineering
strategy?

Moreiras.

On 18/12/13 14:32, Blake Dunlap wrote:
 Regardless of the carriers, you'll find most ASs on the internet only
 listen to /48 or larger. So even if you get your prefixes accepted by your
 provider, don't assume you can get anywhere, or have your packets not fall
 in to uRPF blackholes randomly without a larger aggregate announcement.
 
 -Blake
 
 
 On Wed, Dec 18, 2013 at 10:22 AM, Edward Dore 
 edward.d...@freethought-internet.co.uk wrote:
 
 If you’re talking about announcing each location separately, then RIPE
 have a couple of useful articles about prefix visibility on Ripe Labs:


 https://labs.ripe.net/Members/emileaben/ripe-atlas-a-case-study-of-ipv6-48-filtering
 https://labs.ripe.net/Members/dbayer/visibility-of-prefix-lengths

 Otherwise I guess you’ll need to talk to your chosen carrier(s) about
 aggregating your space for you, which will come down to their policies on
 what routes they will carry internally.

 Edward Dore
 Freethought Internet

 On 18 Dec 2013, at 16:11, Cliff Bowles cliff.bow...@apollogrp.edu wrote:

 I accidentally sent this to nanog-request yesterday. I could use some
 feedback from anyone that can help, please.

 Question: will carriers accept IPv6 advertisements smaller than /48?

 Our org was approved a /36 based on number of locations. The bulk of
 those IPs will be in the data centers. As we were chopping up the address
 space, it was determined that the remote campus locations would be fine
 with a /60 per site. (16 networks of /64). There are usually less than 50
 people at the majority of these locations and only about 10 different
 functional VLANs (Voice, Data, Local Services, Wireless, Guest Wireless,
 etc...).

 Now, there has been talk about putting an internet link in every campus
 rather than back hauling it all to the data centers via MPLS. However, if
 we do this, then would we need a /48 per campus? That is massively
 wasteful, at 65,536 networks per location.  Is the /48 requirement set in
 stone? Will any carriers consider longer prefixes?

 I know some people are always saying that the old mentality of
 conserving space needs to go away, but I was bitten by that IPv4 issue back
 in the day and have done a few VLSM network overhauls. I'd rather not
 massively allocate unless it's a requirement.

 Thanks in advance.

 CWB




 
 This message is private and confidential. If you have received it in
 error, please notify the sender and remove it from your system.




Re: IPv6 /48 advertisements

2013-12-18 Thread Blake Dunlap
Your TE is not the rest of the world's routing slot's problem. Get more
circuits and do your te with your providers directly.

-Blake
On Dec 18, 2013 10:57 AM, Antonio M. Moreiras morei...@nic.br wrote:

 What do you recommend to an end user that have a direct assignment of a
 /48, and would like to disaggregate as part of a traffic engineering
 strategy?

 Moreiras.

 On 18/12/13 14:32, Blake Dunlap wrote:
  Regardless of the carriers, you'll find most ASs on the internet only
  listen to /48 or larger. So even if you get your prefixes accepted by
 your
  provider, don't assume you can get anywhere, or have your packets not
 fall
  in to uRPF blackholes randomly without a larger aggregate announcement.
 
  -Blake
 
 
  On Wed, Dec 18, 2013 at 10:22 AM, Edward Dore 
  edward.d...@freethought-internet.co.uk wrote:
 
  If you’re talking about announcing each location separately, then RIPE
  have a couple of useful articles about prefix visibility on Ripe Labs:
 
 
 
 https://labs.ripe.net/Members/emileaben/ripe-atlas-a-case-study-of-ipv6-48-filtering
  https://labs.ripe.net/Members/dbayer/visibility-of-prefix-lengths
 
  Otherwise I guess you’ll need to talk to your chosen carrier(s) about
  aggregating your space for you, which will come down to their policies
 on
  what routes they will carry internally.
 
  Edward Dore
  Freethought Internet
 
  On 18 Dec 2013, at 16:11, Cliff Bowles cliff.bow...@apollogrp.edu
 wrote:
 
  I accidentally sent this to nanog-request yesterday. I could use some
  feedback from anyone that can help, please.
 
  Question: will carriers accept IPv6 advertisements smaller than /48?
 
  Our org was approved a /36 based on number of locations. The bulk of
  those IPs will be in the data centers. As we were chopping up the
 address
  space, it was determined that the remote campus locations would be fine
  with a /60 per site. (16 networks of /64). There are usually less than
 50
  people at the majority of these locations and only about 10 different
  functional VLANs (Voice, Data, Local Services, Wireless, Guest Wireless,
  etc...).
 
  Now, there has been talk about putting an internet link in every campus
  rather than back hauling it all to the data centers via MPLS. However,
 if
  we do this, then would we need a /48 per campus? That is massively
  wasteful, at 65,536 networks per location.  Is the /48 requirement set
 in
  stone? Will any carriers consider longer prefixes?
 
  I know some people are always saying that the old mentality of
  conserving space needs to go away, but I was bitten by that IPv4 issue
 back
  in the day and have done a few VLSM network overhauls. I'd rather not
  massively allocate unless it's a requirement.
 
  Thanks in advance.
 
  CWB
 
 
 
 
  
  This message is private and confidential. If you have received it in
  error, please notify the sender and remove it from your system.
 




Re: IPv6 /48 advertisements

2013-12-18 Thread Owen DeLong

On Dec 18, 2013, at 08:11 , Cliff Bowles cliff.bow...@apollogrp.edu wrote:

 I accidentally sent this to nanog-request yesterday. I could use some 
 feedback from anyone that can help, please.
 
 Question: will carriers accept IPv6 advertisements smaller than /48?

Generally, no. Since a /48 should represent nothing larger than a single site, 
it's not very reasonable to want to route something longer in general.

 Our org was approved a /36 based on number of locations. The bulk of those 
 IPs will be in the data centers. As we were chopping up the address space, it 
 was determined that the remote campus locations would be fine with a /60 per 
 site. (16 networks of /64). There are usually less than 50 people at the 
 majority of these locations and only about 10 different functional VLANs 
 (Voice, Data, Local Services, Wireless, Guest Wireless, etc...).

That's still poor planning, IMHO. You can easily get more than enough /48s to 
give one to each location. There's absolutely no advantage in the IPv6 world to 
being stingy with address space and no benefit to not putting at least a /48 at 
every location.

You've got 10 VLANs, so you're wasting at most 65,526 networks. Compare that to 
the fact that using a /64 for a VLAN with less than 2,000,000 hosts on it will 
wast at least 18,446,744,073,707,551,616 addresses and you begin to realize 
that sparse addressing in IPv6 and large amounts of excess address capacity are 
intentional.

 Now, there has been talk about putting an internet link in every campus 
 rather than back hauling it all to the data centers via MPLS. However, if we 
 do this, then would we need a /48 per campus? That is massively wasteful, at 
 65,536 networks per location.  Is the /48 requirement set in stone? Will any 
 carriers consider longer prefixes?

Massively wasteful is a fact of life in IPv6. Consider it this way... There are 
two ways to waste address space. One way is, as you describe above, deploying 
it to locations that are unlikely to fully utilize it.

Another way is to leave it sitting in a free pool until long after the protocol 
is no longer useful.

With IPv6, we're not so much choosing between wasting address space or not. 
We're choosing how much address space gets wasted using method 1 vs. how much 
gets wasted using method 2. Ideally, we arrive at the protocol end of life with 
some space remaining in both categories of waste.

 I know some people are always saying that the old mentality of conserving 
 space needs to go away, but I was bitten by that IPv4 issue back in the day 
 and have done a few VLSM network overhauls. I'd rather not massively allocate 
 unless it's a requirement.

It's a requirement and not massively allocating will bite you harder in IPv6 
than space did in IPv4.

IPv4 was designed for a different kind of network. It was designed to support 
some labs and some institutional environments. It was never intended to be the 
global public internet. IPv6 has been designed with the idea of addressing 
absolutely everything from the ground up. The design allows for plenty of /48s 
to number every building that could possibly fit on every planet in the solar 
system and several other solar systems.

Frankly, a /48 per campus is underallocating for any campus that has more than 
one building.

Owen




Re: IPv6 /48 advertisements

2013-12-18 Thread Owen DeLong
Get another /48 for your other location.

Owen

On Dec 18, 2013, at 08:53 , Antonio M. Moreiras morei...@nic.br wrote:

 What do you recommend to an end user that have a direct assignment of a
 /48, and would like to disaggregate as part of a traffic engineering
 strategy?
 
 Moreiras.
 
 On 18/12/13 14:32, Blake Dunlap wrote:
 Regardless of the carriers, you'll find most ASs on the internet only
 listen to /48 or larger. So even if you get your prefixes accepted by your
 provider, don't assume you can get anywhere, or have your packets not fall
 in to uRPF blackholes randomly without a larger aggregate announcement.
 
 -Blake
 
 
 On Wed, Dec 18, 2013 at 10:22 AM, Edward Dore 
 edward.d...@freethought-internet.co.uk wrote:
 
 If you’re talking about announcing each location separately, then RIPE
 have a couple of useful articles about prefix visibility on Ripe Labs:
 
 
 https://labs.ripe.net/Members/emileaben/ripe-atlas-a-case-study-of-ipv6-48-filtering
 https://labs.ripe.net/Members/dbayer/visibility-of-prefix-lengths
 
 Otherwise I guess you’ll need to talk to your chosen carrier(s) about
 aggregating your space for you, which will come down to their policies on
 what routes they will carry internally.
 
 Edward Dore
 Freethought Internet
 
 On 18 Dec 2013, at 16:11, Cliff Bowles cliff.bow...@apollogrp.edu wrote:
 
 I accidentally sent this to nanog-request yesterday. I could use some
 feedback from anyone that can help, please.
 
 Question: will carriers accept IPv6 advertisements smaller than /48?
 
 Our org was approved a /36 based on number of locations. The bulk of
 those IPs will be in the data centers. As we were chopping up the address
 space, it was determined that the remote campus locations would be fine
 with a /60 per site. (16 networks of /64). There are usually less than 50
 people at the majority of these locations and only about 10 different
 functional VLANs (Voice, Data, Local Services, Wireless, Guest Wireless,
 etc...).
 
 Now, there has been talk about putting an internet link in every campus
 rather than back hauling it all to the data centers via MPLS. However, if
 we do this, then would we need a /48 per campus? That is massively
 wasteful, at 65,536 networks per location.  Is the /48 requirement set in
 stone? Will any carriers consider longer prefixes?
 
 I know some people are always saying that the old mentality of
 conserving space needs to go away, but I was bitten by that IPv4 issue back
 in the day and have done a few VLSM network overhauls. I'd rather not
 massively allocate unless it's a requirement.
 
 Thanks in advance.
 
 CWB
 
 
 
 
 
 This message is private and confidential. If you have received it in
 error, please notify the sender and remove it from your system.
 




Re: IPv6 /48 advertisements

2013-12-18 Thread Edward Dore
Yes, from a filtering point of view a /48 in IPv6 is pretty similar to a /24 in 
IPv4, as perfectly illustrated by the two links in my post…

My point was that if you are getting the carrier to do the announcement for you 
then they can announce an aggregated /48 prefix and then break that up inside 
their network (if their internal policies allow it) to give the OP whatever 
prefix length per site they have decided on. The carrier only needs to carry 
the more specific prefixes on their backbone and the rest of the internet sees 
the aggregated prefix.

This all depends on the architecture of the OP’s network and what services they 
are buying from the carrier.

Of course, just getting a /48 per site and doing it properly would be the ideal 
scenario.

Edward Dore 
Freethought Internet 

On 18 Dec 2013, at 16:32, Blake Dunlap iki...@gmail.com wrote:

 Regardless of the carriers, you'll find most ASs on the internet only listen 
 to /48 or larger. So even if you get your prefixes accepted by your provider, 
 don't assume you can get anywhere, or have your packets not fall in to uRPF 
 blackholes randomly without a larger aggregate announcement.
 
 -Blake
 
 
 On Wed, Dec 18, 2013 at 10:22 AM, Edward Dore 
 edward.d...@freethought-internet.co.uk wrote:
 If you’re talking about announcing each location separately, then RIPE have a 
 couple of useful articles about prefix visibility on Ripe Labs:
 
 https://labs.ripe.net/Members/emileaben/ripe-atlas-a-case-study-of-ipv6-48-filtering
 https://labs.ripe.net/Members/dbayer/visibility-of-prefix-lengths
 
 Otherwise I guess you’ll need to talk to your chosen carrier(s) about 
 aggregating your space for you, which will come down to their policies on 
 what routes they will carry internally.
 
 Edward Dore
 Freethought Internet
 
 On 18 Dec 2013, at 16:11, Cliff Bowles cliff.bow...@apollogrp.edu wrote:
 
  I accidentally sent this to nanog-request yesterday. I could use some 
  feedback from anyone that can help, please.
 
  Question: will carriers accept IPv6 advertisements smaller than /48?
 
  Our org was approved a /36 based on number of locations. The bulk of those 
  IPs will be in the data centers. As we were chopping up the address space, 
  it was determined that the remote campus locations would be fine with a /60 
  per site. (16 networks of /64). There are usually less than 50 people at 
  the majority of these locations and only about 10 different functional 
  VLANs (Voice, Data, Local Services, Wireless, Guest Wireless, etc...).
 
  Now, there has been talk about putting an internet link in every campus 
  rather than back hauling it all to the data centers via MPLS. However, if 
  we do this, then would we need a /48 per campus? That is massively 
  wasteful, at 65,536 networks per location.  Is the /48 requirement set in 
  stone? Will any carriers consider longer prefixes?
 
  I know some people are always saying that the old mentality of conserving 
  space needs to go away, but I was bitten by that IPv4 issue back in the day 
  and have done a few VLSM network overhauls. I'd rather not massively 
  allocate unless it's a requirement.
 
  Thanks in advance.
 
  CWB
 
 
 
 
  
  This message is private and confidential. If you have received it in error, 
  please notify the sender and remove it from your system.
 
 
 



RE: IPv6 /48 advertisements

2013-12-18 Thread Eric C. Miller
Owen, thanks for this explanation. +1!



Eric Miller, CCNP
Network Engineering Consultant
(407) 257-5115



-Original Message-
From: Owen DeLong [mailto:o...@delong.com] 
Sent: Wednesday, December 18, 2013 2:07 PM
To: Cliff Bowles
Cc: nanog@nanog.org
Subject: Re: IPv6 /48 advertisements


On Dec 18, 2013, at 08:11 , Cliff Bowles cliff.bow...@apollogrp.edu wrote:

 I accidentally sent this to nanog-request yesterday. I could use some 
 feedback from anyone that can help, please.
 
 Question: will carriers accept IPv6 advertisements smaller than /48?

Generally, no. Since a /48 should represent nothing larger than a single site, 
it's not very reasonable to want to route something longer in general.

 Our org was approved a /36 based on number of locations. The bulk of those 
 IPs will be in the data centers. As we were chopping up the address space, it 
 was determined that the remote campus locations would be fine with a /60 per 
 site. (16 networks of /64). There are usually less than 50 people at the 
 majority of these locations and only about 10 different functional VLANs 
 (Voice, Data, Local Services, Wireless, Guest Wireless, etc...).

That's still poor planning, IMHO. You can easily get more than enough /48s to 
give one to each location. There's absolutely no advantage in the IPv6 world to 
being stingy with address space and no benefit to not putting at least a /48 at 
every location.

You've got 10 VLANs, so you're wasting at most 65,526 networks. Compare that to 
the fact that using a /64 for a VLAN with less than 2,000,000 hosts on it will 
wast at least 18,446,744,073,707,551,616 addresses and you begin to realize 
that sparse addressing in IPv6 and large amounts of excess address capacity are 
intentional.

 Now, there has been talk about putting an internet link in every campus 
 rather than back hauling it all to the data centers via MPLS. However, if we 
 do this, then would we need a /48 per campus? That is massively wasteful, at 
 65,536 networks per location.  Is the /48 requirement set in stone? Will any 
 carriers consider longer prefixes?

Massively wasteful is a fact of life in IPv6. Consider it this way... There are 
two ways to waste address space. One way is, as you describe above, deploying 
it to locations that are unlikely to fully utilize it.

Another way is to leave it sitting in a free pool until long after the protocol 
is no longer useful.

With IPv6, we're not so much choosing between wasting address space or not. 
We're choosing how much address space gets wasted using method 1 vs. how much 
gets wasted using method 2. Ideally, we arrive at the protocol end of life with 
some space remaining in both categories of waste.

 I know some people are always saying that the old mentality of conserving 
 space needs to go away, but I was bitten by that IPv4 issue back in the day 
 and have done a few VLSM network overhauls. I'd rather not massively allocate 
 unless it's a requirement.

It's a requirement and not massively allocating will bite you harder in IPv6 
than space did in IPv4.

IPv4 was designed for a different kind of network. It was designed to support 
some labs and some institutional environments. It was never intended to be the 
global public internet. IPv6 has been designed with the idea of addressing 
absolutely everything from the ground up. The design allows for plenty of /48s 
to number every building that could possibly fit on every planet in the solar 
system and several other solar systems.

Frankly, a /48 per campus is underallocating for any campus that has more than 
one building.

Owen