IPv6 Addressing Tips for ISPs

Alejandro Acosta
by Alejandro Acosta
An operator’s general schema can be compared to a small-scale IANA-RIR schema.

Generally speaking, a provider who obtains an IPv6 address block from its RIR must have an IPv6 addressing plan (just as for IPv4).

Thanks to the huge number of available IPv6 addresses, it has become common practice to assign certain specific block sizes for specific purposes. For example:

  • a) Address blocks for WAN networks
  • b) Address blocks for LAN networks
  • c) Address blocks for loopback interfaces in various devices
  • d) If necessary, address blocks for ULAs (Unique Local IPv6 Unicast Addresses, RFC 4193)
  • e) Address blocks for the network’s core
  • f) Address blocks for customers

For security reasons, blocks and addresses are not assigned consecutively – keep in mind that IPv6 address space is huge and our goal is to make our implementation as secure and vulnerability-free as possible.

Best practices recommend the following:

  • /64s should be assigned for loopbacks
  • /64s for LANs
  • /64s for WANs (otherwise, assign a /127 and reserve the /64)
  • /48s for POPs

It is very important to change our way of thinking, as we are no longer dealing with IPv4 and the need to save address space is no longer a concern.

In practice, we will work with the bits between /32 and /48. It’s actually quite simple. Remember that IPv6 is divided into eight 16-bit fields. What we will now do is play around with some of these fields. In our example, we’ll do the following:

[___ NET ID __ ]  [Subnet]  [Division]   [________  Interface ID ____________]

2001:0db8:0000:0000:0000:0000:0000:0000

[C1]          [C2]         [C3]          [C4]       [C5]       [C6]        [C7]        [C8]

In this case, we’ll use the third field of zeroes (subnet). Here we have 16 bits, enough for 65,536 subnets which we can create to satisfy various needs. A possible addressing plan could be as follows:

Addressing Plan (high level):

a) Loopbacks:

  1. Grab the whole 2001:db8:00000000::/48
  • 2001:db8:0:0::1/64 Loopback #1
  • 2001:db8:0:1::43/64 Loopback #2
  • 2001:db8:0:2::00A7/64 Loopback #3

b) LAN Segments:

  1. Grab the whole 2001:db8:00E::/48
  • 2001:db8:000E:0::/64 LAN Segment  #1
  • 2001:db8:000E:23::/64 LAN Segment  #2
  • 2001:db8:000E:286::/64 LAN Segment  #3

c) WANs

  1. Grab the whole 2001:db8:005A::/48
  • 2001:db8:005A:0::/64 WAN Segment  #1
  • 2001:db8:005A:42::/64 WAN Segment  #1
  • 2001:db8:005A:0C2::/64 WAN Segment  #1

d) POPs

  • 2001:db8:00D9::/48 POP #1
  • 2001:db8:139::/48    POP #1
  • 2001:db8:02FD::/48  POP #1

Additional comments:

1) The assignment of IPv6 prefixes according to service type is worth a brief note. Example: Imagine a datacenter that offers its customers shared hosting services as well as dedicated servers (either physical or virtualized servers). In this case, the service provider can assign different /48s to both platforms. Advantages of this scenario include:

  • Easier to manage quality of service within the provider’s network
  • Flexible, per-service /48 BGP announcements
  • More detailed management of VIP customers
  • Easier troubleshooting

2) Finally, organizations present in multiple countries, provinces or states can implement simple, fun things that will bring long-term benefits. For example: If the company has presence in Argentina, Colombia and Venezuela, the corresponding country codes are 54, 57 and 58. Now check out the third field in the following IPv6 addressing plan:

Block: 2001:db8:0:0:0:0:0:0/32:

  • Argentina:         2001:db8:54:0:0:0:0:0/48
  • Colombia:         2001:db8:57:0:0:0:0:0/48
  • Venezuela:        2001:db8:58:0:0:0:0:0/48

In the case above we used the country codes, but we could also have used state or province codes. Moreover, the third field could be used for the country code and the fourth field for the state.

  • Venezuela: 2001:db8:58:212:0:0:0:0/56  (212 = Caracas)

We hope you find this information useful.

For more information, please visit: www.lacnic.net

No more IPv4 addresses in Latin America and the Caribbean

Latin America and the Caribbean have entered the IPv4 exhaustion phase; the delay in deploying Internet Protocol version 6 in our region is cause for concern.

La Casa de Internet de Latinoamérica y el Caribe, 10 June.- Today, the Internet Address Registry for Latin America and the Caribbean (LACNIC), the organization responsible for assigning Internet resources in the region, announced the exhaustion of its IPv4 address pool and expressed its concern regarding the fact that operators and governments throughout the region are delaying the deployment of Internet Protocol version 6 (IPv6).

LACNIC reported that its pool of available IPv4 addresses reached the 4.194.302 mark, and that this has triggered stricter Internet resource assignment policies for the continent. In practice, this means that IPv4 addresses are now exhausted for Latin American and Caribbean operators.

“This is an historic event; the fact that it was anticipated and announced doesn’t make it any less significant,” said Raúl Echeberría, LACNIC’s CEO. “From now on, LACNIC and its National Registries will only be able to assign very small numbers of IPv4 addresses, and these will not be enough to satisfy our region’s needs.” Since it began operating in 2002, the organization has assigned more than 182 million IPv4 addresses throughout Latin America and the Caribbean.

More information: http://www.lacnic.net/en/web/anuncios/2014-no-hay-mas-direcciones-ipv4-en-lac

LACNIC Meets with Latin-American Authorities and ISPs to Discuss the New Internet Protocol

The Internet Address Registry for Latin America and the Caribbean (LACNIC) has begun, at the beginning of February, a series of visits and meetings with Latin- American officials and operators. The target of this tour is to report on the impending exhaustion of the regional IPv4 address stock and discuss the actions that should be taken to ensure normal Internet growth in that country.

IP addresses are a finite yet vital resource for the proper operation of the Internet, and this year will bring significant challenges resulting mainly from entering a new phase where IP version 4 (IPv4) address availability will be increasingly reduced. In order to make the transition as smooth as possible and ensure continued Internet growth through a safe and stable transition to Internet Protocol version 6 (IPv6) throughout the region, this new phase requires active participation of all stakeholders.

During the months of February and March, LACNIC experts visited government agencies and Internet Service Providers in Venezuela, Panama, Colombia, Ecuador, Peru, Trinidad and Tobago, Chile, and Argentina to raise awareness on the imminent exhaustion of IPv4 and the need to deploy IPv6.

More than six out of ten Internet organizations in the LACNIC service region have already received at least one IPv6 address block, the new technology that now is replacing the IPv4 protocol.

According to LACNIC’s technical records, Brazil leads the ranking of countries with the most IPv6 assignments, followed by Argentina, Colombia, Mexico, Chile, Costa Rica, and Ecuador.

Today, more than five out of ten Latin Americans have Internet access, and this number is expected to grow over the next 30 months. It is estimated that by 2015 there will be 100 million new Internet users in Latin America and the Caribbean, totaling 355 million users in the region.


2012 Year-End IPv4 Status Report

Although it is a well-known fact that IPv4 address space is nearing exhaustion, this document reviews the current global and regional status of IPv4 address availability at the end of 2012. The information contained in this report can be found on the various websites cited throughout this document; however, this information has not been compiled in any single location or translated into the languages spoken in our region.

We assume that the reader is familiar with the current Internet address distribution and allocation system, as well as with the relationship between the IANA, regional registries, and ISPs/end users. For more information, please visit IANA’s website at: http://www.iana.org/numbers

Addresses Available in the IANA Pool

In February 2011, the central stock of IPv4 addresses administered by the Internet Assigned Numbers Authority (IANA) was finally exhausted. At that time, each RIR was assigned one of the five remaining blocks according to the global policy in force. More information on this milestone ceremony can be found at: http://lacnic.net/sp/anuncios/2011-agotamiento-ipv4.html

5414329514_a0a98b066f

A complete distribution map of the original 256 /8 blocks can be found on IANA’s website at the following URL:http://www.iana.org/assignments/ipv4-address-space/ipv4-address-space.xml

Since then, each RIR has only had access to its own IPv4 stock and, consequently, each RIR has had different projected IPv4 exhaustion dates for their region. The current situation for the five RIR service regions is analyzed below.

Addresses Available in RIR Pools

Each regional registry has a policy that is triggered when IPv4 resources reach a “practical” exhaustion limit. This limit is typically reached when a single /8 block remains, although LACNIC reserves two /12 blocks. After this “virtual exhaustion,” regional registries will no longer assign IPv4 addresses based on demonstrated need but will rather set a maximum block size to be assigned per organization – typically a /22. Once this stage is reached, even though the RIR still has some addresses, the RIR stock is considered to be exhausted as it can no longer satisfy the actual needs of ISPs and other organizations.

APNIC

APNIC was the first regional registry to run out of IPv4 addresses. On 15 April, 2011, APNIC started to use its last remaining /8. This event triggered a policy that restricts assignments to a single /22 per organization, either new or pre-existing. More information on APNIC’s website: http://www.apnic.net/publications/news/2011/final-8

It is interesting to analyze the following graph by Geoff Huston which clearly shows how scarcity began in April 2011. While in 2010 the average demand and number of assignments were in the order of 2 million addresses per week, the graph shows that the number of address assignments has been negligible after the “last /8″ policy was triggered. It also clearly shows increased demand during the first weeks of 2011 in anticipation of the moment when that policy would be triggered.

RIPE NCC

On 14 September, 2012, Europe’s regional registry also started to use its last remaining /8. The policy in force states that, from that moment on, the maximum assignment size is a /22. The original announcements from RIPE can be found at the following links:

488308_10152089993770023_1462138364_n

ARIN, LACNIC and AfriNIC

These three registries have not yet reached their last /8 block and there are different estimates as to when each RIR will begin to use their reserve block. One of the better known projected RIR address pool exhaustion date estimates is the one prepared by Geoff Huston and available at the following link: IPv4 Address Report: http://www.potaroo.net/tools/ipv4/index.html

Projected
RIR Address Pool Exhaustion Dates:
RIR Projected
Exhaustion Date
Remaining
Addresses in RIR Pool (/8s)
APNIC:

19-Apr-2011 (actual)

0.8937
RIPE
NCC:

14-Sep-2012 (actual)

0.9457
ARIN:

08-Jun-2014

3.0049
LACNIC:

23-Sep-2014

2.8762
AFRINIC:

22-Feb-2021

3.8043

This information can be seen in graphic form at the following link: http://www.potaroo.net/tools/ipv4/plotend.png

In turn, LACNIC has its own IPv4 exhaustion date projections: http://www.lacnic.net/web/lacnic/reporte-direcciones-ipv4

Also worth mentioning are the comparative reports for the different RIRs regularly published by the NRO (www.nro.org), which can be found at the following link: http://www.nro.net/statistics

Conclusions

As we can see, an important part of the global Internet is based in regions where the regional registries have already exhausted their IPv4 resources and where new IPv4 requests now face strict restrictions. Moreover, based on the projections cited above, we can safely assume that during the second half of the upcoming year most of the Internet will have insufficient IPv4 resources. For all of the above, we should begin thinking that the IPv4 protocol is exhausted and start thinking of an IPv6-based Internet. In our region, particularly, we should consider that we only have a year and a half to adopt the new version of the IP protocol and thus avoid the problems associated with IPv4 exhaustion.

References

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