IPv4 Address LifetimeSANOG IV

Presented by Nurani Nimpuno, APNIC

Research activityconducted by Geoff Huston

and supported by APNIC

Are we running out of IP addresses?

• Recent media reports claiming we are running out of IP addresses– Some claim we’ve already run out in some

parts of the world

• But what are the facts?– Is the IPv4 sky falling?

• Geoff Huston, chief scientist at APNIC, has studied the IPv4 consumption rates

Modeling the Process

1. IETF definition of IPv4– Source: IETF standards (RFCs)

• Delegation of address space for IANA administration

2. IANA allocations to RIRs– Source: IANA IPv4 Address Registry

• Allocation of /8 blocks to RIRs and others

3. RIR allocations to ISPs– Source: RIR Stats files

• Allocation of blocks to LIRs

4. ISP announcements – Source: BGP routing table

• Amount of address space advertised

IETF Reserved, 20.1, 8%

Multicast, 16, 6%

Unicast, 219.9, 86%

1. IETF Delegations – IPv4

Breakdown of IPv4 address Space by /8 block equivalents

IETF Reserved, 20.1, 8%

Multicast, 16, 6%

IANA Pool, 89, 35%

IANA Allocated, 130.9, 51%

IANA Allocations - Current

IANA Allocations - HistoricalIANA Allocated IPv4 /8 Address Blocks

0

20

40

60

80

100

120

140

Jan-91 Jan-93 Jan-95 Jan-97 Jan-99 Jan-01 Jan-03

RIR Allocations - Current

IETF Reserved, 20.1, 8%

Multicast, 16, 6%

IANA Pool, 89, 35%

RIR Pool, 14, 5%

Assigned, 116.9, 46%Allocated

RIR Allocations - Historical

RIR Assigned IPv4 /8 Address Blocks

0

20

40

60

80

100

120

Jan-83 Jan-85 Jan-87 Jan-89 Jan-91 Jan-93 Jan-95 Jan-97 Jan-99 Jan-01 Jan-03

BGP Routing Table

• The BGP routing table spans a set of advertised addresses

– Representing addresses in use by ISPs

• A similar analysis of usage and projection can be undertaken on this data

• Assumption: BGP routing table represents actual IP address usage

– Therefore it “drives” the other trends

BGP Routing Table - Current

IETF Reserved, 20.1, 8%

Multicast, 16, 6%

IANA Pool, 89, 35%

RIR Pool, 14, 5%

Assigned, 42.4, 17%

Advertised, 74.5, 29%

Allocated

BGP Announcements - HistoricalBGP Table - Address Span

0

50

100

150

200

No

v/99

Jan/

00

Ma

r/0

0

Ma

y/0

0

Jul/0

0

Se

p/0

0

No

v/00

Jan

/01

Ma

r/0

1

Ma

y/0

1

Jul/0

1

Se

p/0

1

No

v/0

1

Jan

/02

Ma

r/0

2

Ma

y/0

2

Jul/0

2

Se

p/0

2

Nov

/02

Jan/

03

Ma

r/0

3

Ma

y/0

3

Combining the DataIPv4 Address Space

0

20

40

60

80

100

120

140

Jan-83 Jan-85 Jan-87 Jan-89 Jan-91 Jan-93 Jan-95 Jan-97 Jan-99 Jan-01 Jan-03

IANA

RIR

BGP

Recent DataIPv4 Address Space

0

20

40

60

80

100

120

140

Dec-99 Mar-00 Jun-00 Sep-00 Dec-00 Mar-01 Jun-01 Sep-01 Dec-01 Mar-02 Jun-02 Sep-02 Dec-02 Mar-03 Jun-03

IANA

RIR

BGP

Projections

Projections – IANA & RIR Allocations

• Any projection is very uncertain because of:

– Sensitivity of allocation rate to prevailing RIR policies

– Sensitivity to any significant uptake up of new applications that require end-to-end IPv4 addressing vs use of NATs

Projections – BGP Data

• 3 year data baseline – Much shorter baseline than the IANA and RIR

projections– Considerable uncertainties with this projection

• First order differential of total BGP announcement– Until 2000, exponential growth– Since 2000, oscillating differential and overall

deceleration– Last 6 months, differential approaching 0 (i.e. no

growth)

• Linear fit seems most appropriate for this data

Process model - exponential

2020 2022

0

32

64

96

128

160

192

224

Jan-00 Jan-02 Jan-04 Jan-06 Jan-08 Jan-10 Jan-12 Jan-14 Jan-16 Jan-18 Jan-20 Jan-22 Jan-24 Jan-26 Jan-28

IANA

RIR

BGP

Process model - exponential

2020 2022

2029

0

32

64

96

128

160

192

224

Jan-00 Jan-02 Jan-04 Jan-06 Jan-08 Jan-10 Jan-12 Jan-14 Jan-16 Jan-18 Jan-20 Jan-22 Jan-24 Jan-26 Jan-28

IANARIRBGP

Unnann.

RIR pool

Process model - linear

2047

2031 2037

0

32

64

96

128

160

192

224

Jan-00 Jan-05 Jan-10 Jan-15 Jan-20 Jan-25 Jan-30 Jan-35 Jan-40 Jan-45

IANA

RIR

BGP

Methodology and Caveats

• Projection of based on 2000-2003 data–IANA and RIR allocation practices

–BGP-based demand model

• Incorporating–RIR unallocated pool

–Total address space including allocated but unannounced

• Exponential growth model–Address space lasts until 2022–(or 2029 if all unannounced space recovered)

• Linear growth model–Address space lasts until 2037 (or 2047)

Some Big Issues

• This is just a model - reality will be different!

• Will the BGP routing table continue to reflect allocation rates?

• Is the model of the unannounced pools and RIR holding pools appropriate?

• Externalities…– What are the underlying growth drivers (applications and

services) and how are these best modeled?– What forms of disruptive events would alter this model, and to

what extent?

Concluding thoughts…

• IP address management

– Result of 20 year evolution on the Internet

• Supported Internet growth to date

• We are not running out of IP addresses now

– But impossible to predict future

• Policies change

• New technologies can emerge

• Market behaviour can change

What about IPv6?

• RIRs support the deployment of IPv6

– Transition will take time

• Necessary to start now

• IPv4 was slow to start, but grew exponentially over the last 10 years

– Don’t get left behind!

• Be future ready!

• Responsible management essential to keep the Internet running

Questions?

http://www.potaroo.net

http://www.potaroo.net/ispcolumn/2003-07-v4-address-lifetime/ale.pdf