Running Out of Space: IPv4 Exhaustion Brian Nisbet Network Operations, HEAnet

Introduction IPv4 number pool is finite. –Death of Internet predicted for many years. Growth in use of resource is inexorable. Finite resource will be exhausted. New picture of post-exhaustion life. –Not as "obvious" as it might have seemed.

Some Jargon IANA – Internet Assigned Numbers Authority –Oversees Global IP Address assignment. RIR – Regional Internet Registry –Allocates IP Addresses to LIRs such as HEAnet. The RIR for Europe & Middle-East is RIPE. IPv4 Address Pool –220 /8s (16 million addresses per /8)

Current state (Out of 220 /8s) Geoff Huston –

IANA pool Geoff Huston – Assigned space Today This limit is real! ?

Predicted Timelines Predictive model assumes continued allocation using current policies and with no hoarding, no withholding and no rationing. (No chance). IANA Unallocated Pool – 06 August 2010 RIR Unallocated Pool – 31 May 2011 Maths by Geoff Heuston et al: HEAnet LIR Pool - ? (70% of current allocation is in use.)

What Do the Dates Mean? RIR Unallocated Pool exhaustion means that LIRs will be unable to obtain new IPv4 address space, regardless of need. No more new IPv4 addresses using current policies. Post-exhaustion picture is only now emerging. –Not as simple as most of us first assumed.

Probable Business Effects Massive changes to business practices for existing businesses, especially ISPs, hosting companies etc. Increased use of NAT and similar, especially in residential, slowing deployment of new research. Huge barrier to entry for new companies if IPv4 addresses are scarce/impossible to get. Possible emergence of a market for IPv4 addresses. Increased government & regulator attention.

Probable HEAnet Community Effects Restricted network growth. –New devices (mainly mobile) - e.g. laptops, iPhones, pdas. –No temporary allocations to help network restructuring. More inclination to NAT. –Restriction on your ability to segment/scale your network. –CPU scaling badly with bandwidth growth - NAT becomes the highest element in your connectivity costs. Increased pressure to renumber. Pressure for hurried (= unstable) deployment of IPv6.

Next Steps? Start planning now! Determine current requirements for IPv4 growth. Consider impact of various workarounds. Long term solution is IPv6. –Earlier the start the better - hardware has 5? year lifecycle. –Cooperation with rest of community & industry essential. Consider renumbering large flat networks. –Segmenting provides other benefits also.

Thank you! Questions?