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Internet Engineering Task Force                         S. Tsuchiya, Ed.
Internet-Draft                                               M. Townsley
Intended status: Informational                             Cisco Systems
Expires: May 17, 2012                                          S. Ohkubo
                                                         Sakura Internet
                                                       November 14, 2011


           IPv6 Rapid Deployment (6rd) in a Large Data Center
                     draft-sakura-6rd-datacenter-03

Abstract

   IPv6 Rapid Deployment (6rd) as defined in RFC 5969 focuses on rapid
   deployment of IPv6 by an access service provider which has difficulty
   deploying native IPv6.  This document describes how 6rd can be used
   to deliver IPv6 within a Large Data Center.

Status of this Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
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   Drafts is at http://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on May 17, 2012.

Copyright Notice

   Copyright (c) 2011 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as



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   described in the Simplified BSD License.


Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  3
   2.  Network Architecture . . . . . . . . . . . . . . . . . . . . .  3
   3.  6rd Availability in Server Operating Systems . . . . . . . . .  5
   4.  Deployment Consideration . . . . . . . . . . . . . . . . . . .  6
     4.1.  IPv4 compression address . . . . . . . . . . . . . . . . .  6
     4.2.  Configuration  . . . . . . . . . . . . . . . . . . . . . .  6
     4.3.  MTU consideration  . . . . . . . . . . . . . . . . . . . .  6
     4.4.  Performance  . . . . . . . . . . . . . . . . . . . . . . .  7
   5.  Acknowledgements . . . . . . . . . . . . . . . . . . . . . . .  7
   6.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . .  7
   7.  Security Considerations  . . . . . . . . . . . . . . . . . . .  7
   8.  References . . . . . . . . . . . . . . . . . . . . . . . . . .  7
     8.1.  Normative References . . . . . . . . . . . . . . . . . . .  7
     8.2.  Informative References . . . . . . . . . . . . . . . . . .  7
   Appendix A.  Additional Stuff  . . . . . . . . . . . . . . . . . .  9
     A.1.  OS configuration . . . . . . . . . . . . . . . . . . . . .  9
       A.1.1.  Network Topology&Parameters  . . . . . . . . . . . . .  9
       A.1.2.  configuration procedure  . . . . . . . . . . . . . . . 10
     A.2.  OS Proportion on Sakura's VPS  . . . . . . . . . . . . . . 13
     A.3.  Apache Bench performance test result . . . . . . . . . . . 13
       A.3.1.  Test Topology  . . . . . . . . . . . . . . . . . . . . 13
       A.3.2.  Test method  . . . . . . . . . . . . . . . . . . . . . 14
       A.3.3.  Hardware Configuration . . . . . . . . . . . . . . . . 14
       A.3.4.  Test Result  . . . . . . . . . . . . . . . . . . . . . 14
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 14





















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1.  Introduction

   IPv6 Rapid Deployment (6rd) as defined in RFC 5969 focuses on rapid
   deployment of IPv6 by an access service provider which has difficulty
   deploying native IPv6.  This document describes how one service
   provider in Japan, Sakura Interent, Inc., not for a large residential
   deployment, but for a large data center network.

   While the protocol mechanism of 6rd is unchanged, the deployment
   model varies a bit from the classical "residential home access
   provider" model.

   The motivation for using 6rd is very similar to that of the
   residential case where the service provider would like to offer IPv6
   quickly to those users who want it, but without replacing equipment
   that currently does not support IPv6.

   This document is provided as information to the Internet community.


2.  Network Architecture

   The case study presented here is based on the services provide by
   Sakura Internet Inc. Sakura Internet provides Internet services
   through Internet backbones and large data centers.

   Sakura offers four types of services:

   1.  Housing Service, which provides Collocation and Internet Access
   on 5 urban datacenters (4 in Tokyo, 1 in Osaka)

   2.  Hosting Service, which provides shared service on the servers.

   3.  Dedicated Server Service, which provides customer dedicated
   server with variable OSs.

   4.  Virtual Private Server Service (VPS), which provides guest
   operating system on the Kernel-based Virtual Machine (KVM).

   At the time of this writing, Sakura serves more than 200 Gpbs of
   traffic on its backbones, and around 50,000 dedicated servers,
   Virtual Private Servers, and collocated servers.

   Figure.1 describes server-based 6rd in datacenter's network
   architecture.






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                                   .--.
                                 _(.   `)
                               _(  IPv6  `)_
                              (  Internet   `)
                             ( `  .        )  )
                              `--(_______)---'
                                     |
                               +----------+
                               |  6rd BR  |
                               +----------+
                                     |
             +----------+          .--.
             |6rd CE on |        _(.   `)
             |guest OS  |      _(  IPv4  `)_
             +----------+     (  Backbone   `)     +----------+
             |   KVM    |====( `  .        )  )====|6rd CE on |
             +----------+     `--(_______)---'     |dedicated |
                                     ||            |server    |
                                     ||            +----------+
                                 +----------+
                                 |6rd CE on |
                                 |Housing GW|
                                 +----------+
                                       |
                                 -------------IPv4/IPv6 dual stack
                                   |       |
                               [Server] [Server]

                                 Figure 1

   Sakura has deployed commercial 6rd Border Relays, and relies on CE
   functionality in gateway routers or directly within the operating
   system of the servers.

   In the latter model, there is no need for a CE gateway as the 6rd
   function is implemented directly in the server operating system
   itself.

   -For Housing users, there are two options.  Either the 6rd CE
   function is performed on the Gateway router itself, or the servers
   themselves can run 6rd directly.

   -For Hosting users, IPv6 service can start by deploying 6rd CE
   function on the server OS or guest OS on the KVM.

   Server administrators can start IPv6 service on demand themselves by
   using server-based 6rd.




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   There were some issues when Sakura considers IPv6 deployment on their
   backbone.

   1.Some backbone Layer3 switches are too old.

   IPv6 Switching would be software switching even if IPv4 Switching in
   hardware.  It needs replacement.

   2.Some backbone Layer3 switches required software upgrade.

   IPv6 supports on hardware.  But software upgraded is needed.  In
   datacenter, there is different requirement on each server, even if
   the server connected to the same switch.  Because the server
   administrator are completely different.  Each server is providing
   different service to the different customers.  So backbones
   maintenance time negotiation to the customer is very difficult.

   3.Design Consideration

   There are some scalability issues within the large
   datacenter.Especially backbone Layer 3 switches has huge arp and IPv4
   routing entries.When the switch would upgrade and enable IPv6,NDP
   entry will be added,many resource such as NVRAM and TCAM will be
   consumed.

   IPv6 datacenter also has security issues such as
   [draft-ietf-v6ops-v6nd-problems] and [RFC6104].

   To provide native IPv6 service to the existing customer today
   rapidly, it needs cost,time,negotiation with customer and design
   consideration.

   This is the reason why Sakura decided to provide server-based 6rd to
   the existing customer.


3.  6rd Availability in Server Operating Systems

   In particular for the server-initiated case, Sakura relies on 6rd
   availability in Server operating systems.

   Linux kernel has started to support 6rd since 2.6.33.  So if Linux
   based Operating Systems are using 2.6.33 and the later,it can
   provides server-based 6rd.

   FreeBSD and CentOS could not provide 6rd in default, but the patch
   exist.




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   +----------------------+---------------+----------------------------+
   | Operating Systems    |  Linux Kernel |                Description |
   +----------------------+---------------+----------------------------+
   | Fedora14 and the     |    2.6.35 and |     Server-based 6rd ready |
   | later                |         above |                            |
   | Ubuntu 10.10 and the |    2.6.35 and |     Server-based 6rd ready |
   | later                |         above |                            |
   | Debian6.0            |        2.6.32 |        Kernel update needs |
   | CentOS5.6            |        2.6.18 |              needs [CentOS |
   |                      |               |     patch1][CentOS patch2] |
   | FreeBSD8             |           N/A |          needs [BSD patch] |
   +----------------------+---------------+----------------------------+


4.  Deployment Consideration

4.1.  IPv4 compression address

   6rd protocol specification is defined on [RFC5969].  Section 4 of
   [RFC5969] describes o-bit which can compress 32 bit IPv4 address in
   the 6rd delegated prefix.  Linux Kernel also supports this feature.

   So customer could get some IPv6 prefixes even if datacenter's prefix
   is /32.

   But [BSD patch] doesn't has the feature of aggregate IPv4 address,
   therefore datacenter provider has to prepare /32 IPv6 prefix at least
   in that case.

   In Sakura's case, 6rd prefix address using /32, and no compression
   IPv4 address.Thus the delegated 6rd address length is /64.  It is
   enough address space for server-based 6rd.

4.2.  Configuration

   Section 7.1 of [RFC5969] describes 6rd CE automatic configuration
   method such as DHCP,TR-69 and so on.

   But server-based 6rd does not needs automatic configuration because
   the server usually configure IPv4 address statically.

4.3.  MTU consideration

   Section 9.1 of [RFC5969] describes about Maximum Transmission
   Unit(MTU) on 6rd tunnel.  This guide also applicable for server-based
   6rd.

   But datacenter's IPv4 network is well-managed and is known by the



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   server administrator.  So 6rd CE's tunnel MTU could set be -20 byte
   from IPv4 MTU.

   If the 6rd CE would be TCP server such as WWW, TCP MSS(Maximum
   Segment Size will be calculated automatically from tunnel MTU.

4.4.  Performance

   6rd is tunnel technology, therefore the problem of performance is
   often taken up.It depends on server spec,but [ApacheBench] showed
   similar result with IPv4,IPv6 and 6rd.In Sakura internet server
   service,interface specifications are shared 100Mbps for VPS
   server,1Gbps for dedicated server.  The result is enough to provide
   to customer.


5.  Acknowledgements

   The authors thank Hiroki Sato and Masakazu Asama,who made BSD&CentOS
   patch.


6.  IANA Considerations

   This document has no actions for IANA.


7.  Security Considerations

   This document has no security considerations.


8.  References

8.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC5969]  Townsley, W. and O. Troan, "IPv6 Rapid Deployment on IPv4
              Infrastructures (6rd) -- Protocol Specification",
              RFC 5969, August 2010.

8.2.  Informative References

   [ApacheBench]
              ""ab - Apache HTTP server benchmarking tool"",
              <http://httpd.apache.org/docs/2.2/programs/ab.html>.



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   [BSD patch]
              ""BSD patch"", <http://people.allbsd.org/~hrs/FreeBSD/
              stf_6rd_20100923-1.diff>.

   [CentOS]   ""The Community ENTerprise Operating System"",
              <http://www.centos.org/>.

   [CentOS patch1]
              ""CentOS Kernel patch"", <http://enog.jp/~masakazu/6rd/
              kernel-2.6.18-238.9.1.el5.6rd.x86_64.rpm>.

   [CentOS patch2]
              ""CentOS iproute patch"", <http://enog.jp/~masakazu/6rd/
              iproute-2.6.18-11.6rd.x86_64.rpm>.

   [Debian]   ""Debian -- The Universal Operating System"",
              <http://www.debian.org/>.

   [Fedora]   ""Fedora Project Homepage"", <http://fedoraproject.org/>.

   [FreeBSD]  ""The FreeBSD Project"", <http://www.freebsd.org/>.

   [I-D.ietf-armd-problem-statement]
              Narten, T., "Problem Statement for ARMD",
              draft-ietf-armd-problem-statement-00 (work in progress),
              October 2011.

   [I-D.ietf-v6ops-v6nd-problems]
              Kumari, W., "Operational Neighbor Discovery Problems",
              draft-ietf-v6ops-v6nd-problems-00 (work in progress),
              October 2011.

   [Linux 2.6.33]
              ""sit: 6rd (IPv6 Rapid Deployment) Support."",
              <http://kernelnewbies.org/Linux_2_6_33>.

   [RFC3849]  Huston, G., Lord, A., and P. Smith, "IPv6 Address Prefix
              Reserved for Documentation", RFC 3849, July 2004.

   [RFC5569]  Despres, R., "IPv6 Rapid Deployment on IPv4
              Infrastructures (6rd)", RFC 5569, January 2010.

   [RFC5737]  Arkko, J., Cotton, M., and L. Vegoda, "IPv4 Address Blocks
              Reserved for Documentation", RFC 5737, January 2010.

   [RFC5952]  Kawamura, S. and M. Kawashima, "A Recommendation for IPv6
              Address Text Representation", RFC 5952, August 2010.




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   [RFC6104]  Chown, T. and S. Venaas, "Rogue IPv6 Router Advertisement
              Problem Statement", RFC 6104, February 2011.

   [Ubuntu]   ""Ubuntu Homepage"", <http://www.ubuntu.com/>.


Appendix A.  Additional Stuff

A.1.  OS configuration

A.1.1.  Network Topology&Parameters

   Describes configuration of each on OS,for reference.


                                .--.
                              _(.   `)
                            _(  IPv6  `)_
                           (  Internet   `)
                          ( `  .        )  )
                           `--(_______)---'
                                  |
                            +----------+
                            |  6rd BR  |
                            +----------+
                                  |    203.0.113.1
                                .--.
                              _(.   `)
                            _(  IPv4  `)_
                           (  Backbone   `)    6rd prefix:2001:db8::/32
                          ( `  .        )  )
                           `--(_______)---'
                                  |
               --------------------------------------------    203.0.113.0/24
                    |.10     |.11    |.12     |.13      |.14
                [Ubuntu] [Fedora] [Debian] [CentOS] [FreeBSD]


                                 Figure 2

   common parameter

   +-----------------+---------------+-------------+
   | BR IPv4 address | 6rd prefix    | IPv4MaskLen |
   +-----------------+---------------+-------------+
   | 203.0.113.1     | 2001:db8::/32 | 0           |
   +-----------------+---------------+-------------+




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   individual parameter

   +-----------+--------------+-------------------------+
   | OS        | IPv4 address | 6rd delegated prefix    |
   +-----------+--------------+-------------------------+
   | [Ubuntu]  | 203.0.113.10 | 2001:db8:cb00:710a::/64 |
   | [Fedora]  | 203.0.113.11 | 2001:db8:cb00:710b::/64 |
   | [Debian]  | 203.0.113.12 | 2001:db8:cb00:710c::/64 |
   | [CentOS]  | 203.0.113.13 | 2001:db8:cb00:710d::/64 |
   | [FreeBSD] | 203.0.113.14 | 2001:db8:cb00:710e::/64 |
   +-----------+--------------+-------------------------+

A.1.2.  configuration procedure

A.1.2.1.  Ubuntu

   -modify "/etc/network/interfaces"

   # vi /etc/network/interfaces
   auto tun6rd
   iface tun6rd inet6 v4tunnel
     address 2001:db8:cb00:710a::1
     netmask 32
     local 203.0.113.10
     endpoint any
     gateway ::203.0.113.1
     ttl 64
     up ip tunnel 6rd dev tun6rd 6rd-prefix 2001:db8::/32
     up ip link set mtu 1280 dev tun6rd

   -reboot

A.1.2.2.  Fedora

   -make "/etc/sysconfig/network-scripts/ifcfg-sit1"

   # vi /etc/sysconfig/network-scripts/ifcfg-sit1
   DEVICE=sit1
   IPV6INIT=yes
   IPV6_MTU=1280
   IPV6_DEFAULTGW=::203.0.113.1
   IPV6TUNNELIPV4=any
   IPV6TUNNELIPV4LOCAL=203.0.113.11
   IPV6ADDR=2001:db8:cb00:710b::1/32


   -modify "/etc/rc.local"




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   # vi /etc/rc.local
   ip tunnel 6rd dev sit1 6rd-prefix 2001:db8::/32

   -reboot

A.1.2.3.  Debian

   The latest version of Debian is 6.0.Debian6.0's kernel is 2.6.32.So
   it is required upgrade kernel.

   -modify "/etc/apt/sources.list"

   # vi /etc/apt/sources.list
   deb http://ftp.jp.debian.org/debian experimental main
   deb-src http://ftp.jp.debian.org/debian experimental main

   -upgrade kernel

   # apt-get update
   # apt-get -t experimental install linux-image-2.6.38-rc6-amd64

   -reboot

   -modify "/etc/network/interfaces"

   # vi /etc/network/interfaces
   auto tun6rd
   iface tun6rd inet6 v4tunnel
     address 2001:db8:cb00:710c::1
     netmask 32
     local 203.0.113.12
     endpoint any
     gateway ::203.0.113.1
     ttl 64
     up ip tunnel 6rd dev tun6rd 6rd-prefix 2001:db8::/32
     up ip link set mtu 1280 dev tun6rd

   -reboot

A.1.2.4.  CentOS

   The latest version of CentOS is 5.5.CentOS5.5's kernel and iproute
   package does not supported 6rd.So it is required patch.

   -download package

# wget http://enog.jp/~masakazu/6rd/kernel-2.6.18-238.9.1.el5.6rd.x86_64.rpm
# wget http://enog.jp/~masakazu/6rd/iproute-2.6.18-11.6rd.x86_64.rpm



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   -install package

   # rpm -ivh kernel-2.6.18-238.9.1.el5.6rd.x86_64.rpm
   # rpm -Uvh iproute-2.6.18-11.6rd.x86_64.rpm

   -modify "/etc/yum.conf"

   # vi /etc/yum.conf
   exclude=kernel*,iproute

   -modify "/etc/sysconfig/network-scripts/ifcfg-sit1"

   # vi /etc/sysconfig/network-scripts/ifcfg-sit1
   DEVICE=sit1
   IPV6INIT=yes
   IPV6_MTU=1280
   IPV6_DEFAULTGW=::203.0.113.1
   IPV6TUNNELIPV4=any
   IPV6TUNNELIPV4LOCAL=203.0.113.13
   IPV6ADDR=2001:db8:cb00:710d::1/32

   modify "/etc/rc.local"

   # vi /etc/rc.local
   ip tunnel 6rd dev sit1 6rd-prefix 2001:db8::/32


   -reboot

A.1.2.5.  FreeBSD

   FreeBSD does not support 6rd yet.But the patch exists.

   -download patch

   # cd /root
   # fetch http://people.allbsd.org/~hrs/FreeBSD/stf_6rd_20100923-1.diff

   -apply patch

   # cd /usr/src
   # patch -p0 < /root/stf_6rd_20100923-1.diff


   -kernel module compile and install

   # cd sys/modules/if_stf/
   # make



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   # make install

   -install manual

   # cd /usr/src/share/man/
   # make
   # make install

   -modify "/etc/rc.conf"

   # vi /etc/rc.conf
   ipv6_enable="YES"
   cloned_interfaces="stf0"
   ipv6_ifconfig_stf0="2001:db8:cb00:710e::1/32"
   ipv6_defaultrouter="2001:db8:cb00:7101::1"

   -reboot

A.2.  OS Proportion on Sakura's VPS

   The data of OS proportion on Sakura's VPS.

   All of OSs could server-based 6rd.

   +-------------------+---------------+
   | Operating Systems | Proportion[%] |
   +-------------------+---------------+
   | Ubuntu            |            31 |
   | Fedora            |             6 |
   | Debian            |            13 |
   | CentOS            |            39 |
   | FreeBSD           |            11 |
   +-------------------+---------------+

A.3.  Apache Bench performance test result

A.3.1.  Test Topology

   Measurement method of http performance using [ApacheBench].

   Two servers connected to each other and excute [ApacheBench] from
   Client









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                                 Figure 3

A.3.2.  Test method

   Two servers connected to each other.

   Configure transport IPv4,IPv6 and 6rd.

   Executes [ApacheBench] with 100 multiple and total 1000 requests from
   Client

A.3.3.  Hardware Configuration

   In this test cases,harware configuration is below.

   +-----------------------+----------------+---------------+-------+
   |          CPU          |     Hyper-V    |       OS      |  NIC  |
   +-----------------------+----------------+---------------+-------+
   | Intel Xeon3060 2.4GHz | VMware ESX 4.1 | Ubuntsu 10.10 | E1000 |
   +-----------------------+----------------+---------------+-------+

A.3.4.  Test Result

   +----------------------------+----------+----------+----------+
   |          test item         |     IPv4 |     IPv6 |      6rd |
   +----------------------------+----------+----------+----------+
   |      Complete requests     |     1000 |     1000 |     1000 |
   |       Failed requests      |        0 |        0 |        0 |
   | Requests per second[#/sec] |     1.11 |     1.10 |     1.05 |
   |    Time per request[ms]    |  900.598 |  912.586 |  951.868 |
   |  Transfer rate[Kbytes/sec] | 113702.5 | 112208.9 | 107578.2 |
   +----------------------------+----------+----------+----------+


Authors' Addresses

   Shishio Tsuchiya (editor)
   Cisco Systems
   Shinjuku Mitsui Building, 2-1-1, Nishi-Shinjuku
   Shinjuku-Ku, Tokyo  163-0409
   Japan

   Phone: +81 3 6434 6543
   Email: shtsuchi@cisco.com







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   Mark Townsley
   Cisco Systems
   L'Atlantis, 11, Rue Camille Desmoulins ISSY LES MOULINEAUX
   ILE DE FRANCE  92782
   FRANCE

   Phone: +33 15 804 3483
   Email: mark@townsley.net


   Shuichi Ohkubo
   Sakura Internet
   33F Sumitomo fudosan Nishi shinjuku Bldg.,7-20-1 Nishi shinjuku
   Shinjuku-Ku, Tokyo  160-0023
   Japan

   Phone: +81 3 5332 7070
   Email: ohkubo@sakura.ad.jp

































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