IPv6 and Google
Erik Kline <ek@google.com>
Global IP Business Exchange 2011

Why?

IPv4 addresses are gone
The last 2 free /8s were issued 2011年 01月 31日 (月)From IANA's IPv4 address allocation page:039/8 APNIC
106/8 APNIC

2011-01 whois.apnic.net ALLOCATED
2011-01 whois.apnic.net ALLOCATEDThe final 5 free /8s will be distributed 1 to each RIR, perpolicy
estimated RIR runout is 5-6 months from today
Watch special announcement live, Thursday, 3 February
2011, at 09:30 (UTC -5), on nro.net

Why IPv6? Cost
Buying IPv4 addresses will be expensive
Carrier-grade NAT may be expensive
Lots of session state memory
Session logging for legal reasons
Constrains performance
Being behind a NAT is hard to manage
Can't fix problems without NAT operator's help
VPN, VOIP, video streaming, gaming, P2P
Expensive in operator time, support costs
Network complexity creates operation / support costs

Why IPv6? Address semantics
With carrier-grade NAT, users share IP addresses
Less accurate geolocation
Content licensing for streaming, etc.
Abuse identification / blocking
If an IPv4 address is spamming/hacking/...
Who is responsible?
If we block it, do we take out 100 users?
Different from blocking a proxyIP-based authentication
Of course, nobody would ever do thisWhy IPv6? Opportunity
We see a growing number of IPv6-only deployments
Set-top boxes (free.fr, Comcast, ...)NTT IPTV over IPv6 ("walled garden", though)Mobile networks (LTE, NAT64, ...)
There is simply not enough address space to assign IPv4
addresses to these devices
NAT is too expensive
CPU on home gateway
CPU on routers
Want to talk to these devices? Need to use IPv6

Why IPv6? New applications
The Internet was successful because of end-to-end
Users still want end-to-end!
Skype, Bittorrent, ...
Neither of these could have been developed in theabsence of public IP addresses
What happens if this goes away?
Will the Internet become like TV?
Will the Internet become like the phone network?
Will any Internet communication require ISP support?

The Internet without IPv6

IP address sharing

TCP port overload

Content inspection/rewriting

Barriers to innovation

The search for the killer application
Many are waiting for a "killer application" for IPv6
This is a misconception
It's not "what can IPv6 do better than IPv4?"
It's "can the Internet as we know it continue to operateusing IPv4?"
The killer application of IPv6 is the survival of the open
Internet as we know itWhy IPv6 at Google?
When the day comes that users only have IPv6, Google
needs to be there for themServe current users better over IPv6
IPv6 can have lower latency and packet loss
We have user reports to prove it
AJAX applications break behind excessive NAT
Connections exhaust public IP port space
Growing number of IPv6-only client deployments
Set-top boxes, mobile, ...
IPv6 is good for the Internet, and we want to help

So what have we done?

Leading the industry since 2008

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Enable IPv6 for www.google.com?
We can't enable IPv6 for www.google.com today~0.05% users won't reach Google any more
Broken home gateways, DNS forwarders, ...
If the user has a problem, they can't reach Google
to search for a fix
1 / 2000 is a lot of users!
Many users would have higher latency
Long paths, suboptimal routing, tunnels...
Bad and incomplete routing is there, but you can'tsee or fix it if there's nowhere useful to go
This has gotten much better now

Providing reliable services over IPv6
Avoid bad routing by avoiding transit, prefix limits
Peer with almost everybody
Bring the network as close to the user as possible
Serve IPv6 only to production-quality user networks

Google over IPv6Enables IPv6 access to Google for selected networks
IPv6 access to most Google web properties
www, mail, news, docs, youtube, ...
still more to come
Which ones do you and your users want?
Requirements:
Good IPv6 connectivity to Google
Production-quality IPv6 network
Commitment to fix problems that break Google forusersHow it works
Normally, if a DNS resolver requests an IPv6 address for a Google web site, itwill not receive one…

…but a DNS resolver with Google over IPv6 will receive an IPv6 address, andits users will be able to connect to Google web sites using IPv6.

http://www.google.com/ipv6/

Results so far
Enthusiastic response:Over 80 organizations participating
Universities, research institutions, an NREN
One large French access provider~ 75% of the native IPv6 Internet
Feedback so far has been positive
Some networks see better IPv6 routing than IPv4
Now enough IPv6 traffic that problems get reported
Allows participants to bypass IPv4 congestion
Want to take part? Let us know!
google.com/ipv6

Lessons learned

High-level strategy
Start with user-visible services
Gives other networks reason to deploy
Breaks the chicken and egg cycle
Only 0.1% of users have IPv6, so scaling is easy
Start with prototype infrastructure and work inwards:
1. External networking
2. Frontend serving systems
3. User services
4. Backend networking, internal applications
Use shim layers to protect code/infrastructure that doesn't
understand IPv6

Methodology
Tap enthusiasm
Started as 20% project, great influx of contributors
Make it easy for contributors to get initial results
A pilot network is not expensive
Once the network is up, internal applications follow
Do it in stages
v6 needn't be as capable as v4 on day one
But it must be done properly
If it's not production-quality, it's of no use to anyone
Fold it into your normal upgrade cycles

Timeline
April 2005

Obtain and announce address space

...

...

July 2007

Network architecture and software engineering begin (20%)

December 2007

Mark Townsley challenges Google to serve IPv6 by IETF 73

January 2008

First pilot router. Google IPv6 conference, Google over IPv6 for attendees

March 2008

ipv6.google.com (IETF 72)

Q3 2008

ipv6.google.cn, ipv6.google.co.jp

November 2008

First Google over IPv6 networks enabled. Google over IPv6 at RIPE / IETF / ...

January 2009

Google over IPv6 publicly available

March 2009

Google maps available over IPv6, 3x increase in traffic

August 2009

IPv6 enabled in Android (available on Droid and Nexus One)

February 2010

Youtube available over IPv6, 10x increase in traffic

And all this with a small core team

Statistics

Global IPv6 adoption

google.com/ipv6/statistics

Traffic can appear overnight(Maps enabled for Google over IPv6 users on 2009-03-19)

Traffic can appear overnightGoing forward

User IPv6 connectivity is often broken
Misbehaving home routers, Internet Connection Sharing,or "rogue RAs"
User misconfiguration
Firewalls that don't understand and block IPv6
Path MTU discovery may be blocked
Unreliable or slow transition mechanisms
Applications that are not fault-tolerant or do not "fail fast"It looks like Google is broken
All other dual-stack sites are broken as well...but user may not notice
User doesn't realize there is a problem
Never calls ISP
Suffers in silence, goes to another website, ...
Our data shows that ~0.05% of users have this problem
All the time, every time they connect
This is the #1 reason content providers cannot enable IPv6

Measuring brokenness
Ask browser to connect to IPv4 and dual-stack hosts
Use Javascript to make multiple requests"Sentinel" after fixed time checks if user disconnected
Can run on multiple properties
Use one-time hostnames
Uniquely identifies / associates measurements
Finds out if browser asked for AAAA, A and when
Prevents browsers caching JavascriptWorld IPv6 Day
2011年 6月 8日
http://isoc.org/worldipv6day
http://www.attn.jp/worldipv6day (日本語で)Coordinated, global awarenessAttempt to test at scale
Content sites include:{facebook,google,yahoo,youtube}.com
Akamai and Limelight -hosted sites may choose to...and many others
Join us!

質問?

ありがとう!
google.com/ipv6ek@google.com