The document discusses the current state of IPv4 and IPv6 addresses. It notes that IPv4 addresses are rapidly depleting, with only 5% remaining in 2011. As IPv4 addresses run out, network operators are transitioning to IPv6, though adoption has faced challenges. The RIPE NCC is gradually reducing the allocation periods for IPv4 addresses and will implement a final allocation policy of one /22 block once its pool is exhausted. Various techniques like network address translation and tunnels are being used to extend the IPv4 pool and facilitate the transition to IPv6 during depletion.

1. IPv4 and IPv6
current situation
Marco Hogewoning, trainer

2. IPv4 addresses in the global pool
40% 38%
36%
34%
32%
30%
30%
26%
22%
20%
17%
13%
10% 9%
5%
0%
2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Marco Hogewoning, 17 November 2011 2

3. Reaching the next level
• The Internet has around 2 billion users
• They consumed 3.5 billion addresses
• Growing in all directions
– More users join up
– More connections become ‘always on’
– More devices become ‘Internet aware’
• IPv4 can no longer sustain this growth
Marco Hogewoning, 17 November 2011 3

4. IPv4 exhaustion phases
IPv4 still available.
Final /8 policy RIPE NCC can only
RIPE NCC continues
triggered distribute IPv6
normal operation
now time
IANA pool RIPE NCC RIPE NCC
exhausted reaches pool
final /8 exhausted
Each of
the 5 RIRs
received
a /8
Marco Hogewoning, 17 November 2011 4

5. Business as usual
• As long as there are IPv4 addresses left, the
RIPE NCC will keep on distributing them, based
on justified need
• Same allocation and assignment policies still
apply (RIPE-530)
• Until the final /8 is reached
Marco Hogewoning, 17 November 2011 5

6. “Run Out Fairly”
• Gradually reduced allocation and assignment
periods
• Needs for “Entire Period” of up to...
– 12 months (January 2010)
–9 months (July 2010)
–6 months (January 2011)
–3 months (July 2011)
• 50% has to be used up by half-period
Marco Hogewoning, 17 November 2011 6

7. Final /8 policy
• Each LIR can get one /22 allocation
– 1024 IPv4 addresses
– New and existing members
– As long as supplies will last
• You must meet the criteria for an (additional)
allocation
• Only when you already have IPv6 addresses
Marco Hogewoning, 17 November 2011 7

8. Transfer of IPv4 allocations
• LIRs can transfer IPv4 address blocks:
– To another LIR
– Only when the block is not in use
– Meets minimum allocation size (/21)
• Requests are evaluated by the RIPE NCC
– Justified need
• Registered in the RIPE Database
Marco Hogewoning, 17 November 2011 8

9. No changes yet
• Policy will only change when the RIPE NCC’s
final /8 is reached
• Be aware of the shorter assignment period!
• And start deploying IPv6 now!
Marco Hogewoning, 17 November 2011 9

10. Other RIRs
• APNIC ran out on 14 April 2011, final /8 policy
activated. Now allocating a maximum of /22
• ARIN plans for /28 - /24 when reaching final /8
• LACNIC policy is /22 for ISP, /24 for critical
infrastructure
• AfriNIC has no specific final /8 policy
See http://www.nro.net/rir-comparative-policy-overview
Marco Hogewoning, 17 November 2011 10

11. RIPE NCC Available Pool
http://www.ripe.net/internet-coordination/ipv4-exhaustion/ipv4-available-pool-graph
Marco Hogewoning, 17 November 2011 11

12. IPv4 vs IPv6

13. Address format
• IPv4 uses 32 bit addresses
– ‘Dotted decimal’
– 0.0.0.0 - 255.255.255.255
• IPv6 uses 128 bit addresses
– Hexadecimal notation, numbers between 0 and f
– Separated by colons
– ‘2001:980:3042:2:5a55:caff:fef6:bdbf’
• IPv4 and IPv6 are not compatible
Marco Hogewoning, 17 November 2011 13

14. Coexistence
• IPv4 and IPv6 can not talk to each other
• But they can exist together on the same network
• Known as ‘Dual stack’
– Computer has both an IPv4 and IPv6 address
– Uses one of the two when communicating
– If IPv6 is available it usually has preference
Marco Hogewoning, 17 November 2011 14

15. A perfect world
IPv4 you
IPv6
Marco Hogewoning, 17 November 2011 15

16. The plan (1995 - 2009)
• To have most computers and networks dual
stacked before the IPv4 pool runs out
• Traffic would have switched to IPv6
• Smooth transition from IPv4 to IPv6
• This failed :(
Marco Hogewoning, 17 November 2011 16

17. IPv6 deployment issues
• People are reluctant to change
– If it isn’t broken...
• Changes cost money
• There wasn’t a business case
– IPv4 run out was a long term problem
– It is a ‘hidden’ problem
• Equipment wasn’t available
– Cause or side-effect ?
Marco Hogewoning, 17 November 2011 17

18. Alternatives

19. Extending the IPv4 pool
• Find unused addresses
• Use Network Address Translation (NAT)
– Common technique in home environments
– Machines get a ‘private IP address’
– And share a single public IP for connections
• Do the same at the operator level
– Customers will get a private IP
– Carrier Grade NAT/Large Scale NAT
Marco Hogewoning, 17 November 2011 19

20. Problems with NAT
• Does it really scale ?
– How many users can share a single address ?
• Who is using address X ?
– Who am I talking to ?
– Who to blame for abuse ?
• It doesn’t allow to offer services
• Some protocols will break
• It does not talk to IPv6!
Marco Hogewoning, 17 November 2011 20

21. Plan B
• Technical community is very active
• Countless protocols and proposals are around
– 6in4
– 6to4
– 6RD
– TSP
– A+P
– 4RD
– ...etc
Marco Hogewoning, 17 November 2011 21

22. Transitioning techniques
• Most of them use ‘tunnels’
– Put X in Y (IPv6 in IPv4)
• The end point has both protocols
• And the network in between doesn’t
• Requires assistance in the form of so called
‘tunnel servers’
– ‘Bridge’ between the 2 worlds
– Unpacking and repacking the data
Marco Hogewoning, 17 November 2011 22

23. Tunnels
Tunnel
IPv4 server IPv6
Marco Hogewoning, 17 November 2011 23

24. Drawbacks of tunnels
• Still require (public) IPv4 addresses
• Most of them work one way (IPv4 -> IPv6)
– IPv6 content ?
• Who owns the tunnel server ?
– Does it come with some guarantee ?
– Can you trust them ?
– ‘man in the middle’
• Filtering prohibits tunnels
Marco Hogewoning, 17 November 2011 24

25. Translation (NAT64/NAT-PT)
• Alternative #3: translate IPv4 into IPv6
• Customer will only get one protocol
• Translator box sits in between
– Talks to both IPv4 and IPv6
– Shares addresses
• Drawbacks
– Who is who
– Can you trust the ‘man in the middle’
– Breaks DNSsec
Marco Hogewoning, 17 November 2011 25

26. Dual stack where you can
• “The most customer friendly way of transitioning
to IPv6”
• Long term solution
• IPv4 run out is everybody’s problem
• The key in solving it lies with those who already
have IPv4 addresses
• Worst case scenario: split brain!
Marco Hogewoning, 17 November 2011 26

27. IPv6 statistics
Marco Hogewoning, trainer

28. IPv6 RIPEness
• Rating system:
– One star if the member has an IPv6 allocation
– Additional stars if:
- IPv6 Prefix is visible on the internet
- A route6 object is in the RIPE Database
- Reverse DNS is set up
–A list of all 4 star LIRs: http://ripeness.ripe.net/
Marco Hogewoning, 17 November 2011 28

29. IPv6 RIPEness: 7819 LIRs
1 star
14%
2 stars
5%
No IPv6
54%
3 stars
11%
4 stars
16%
Marco Hogewoning, 17 November 2011 29

30. IPv6 RIPEness over time
100%
80%
60%
40%
20%
0%
09-2010 11-2010 01-2011 03-2011 05-2011 07-2011 09-2011 11-2011
No IPv6 1 star 2 star 3 star 4 star
Marco Hogewoning, 17 November 2011 30

31. Questions?

32. The End! Kрай Y Diwedd
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