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 Process1. 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 - HistoricalRIR 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

Nov/

99

Jan/

00

Mar

/00

May

/00

Jul/0

0

Sep/

00

Nov/

00

Jan/

01

Mar

/01

May

/01

Jul/0

1

Sep/

01

Nov/

01

Jan/

02

Mar

/02

May

/02

Jul/0

2

Sep/

02

Nov/

02

Jan/

03

Mar

/03

May

/03

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

IANARIRBGP

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

IANARIRBGP

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

IANARIRBGP

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

IANARIRBGPUnnann.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

IANARIRBGP

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?

gih@telstra.nethttp://www.potaroo.net

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