Internet Engineering Task Force S. Tsuchiya, Ed.
Internet-Draft M. Townsley
Intended status: Informational Cisco Systems
Expires: January 12, 2012 S. Ohkubo
Sakura Internet
July 11, 2011
IPv6 Rapid Deployment (6rd) in a Large Data Center
draft-sakura-6rd-datacenter-01
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
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This Internet-Draft will expire on January 12, 2012.
Copyright Notice
Copyright (c) 2011 IETF Trust and the persons identified as the
document authors. All rights reserved.
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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
5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 6
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 . . . . . . . . . . . . . . . . . . 8
A.1. OS configuration . . . . . . . . . . . . . . . . . . . . . 8
A.1.1. Network Topology&Parameters . . . . . . . . . . . . . 8
A.1.2. configuration procedure . . . . . . . . . . . . . . . 10
A.2. OS Proportion on Sakura's VPS . . . . . . . . . . . . . . 13
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 13
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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 switches are too old.
IPv6 Switching would be software switching even if IPv4 Switching in
hardware. It needs replacement.
2.Some backbone 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.
To provide native IPv6 service to the existing customer, it needs
cost,time and negotiation.
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.
+----------------------+---------------+----------------------------+
| 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] |
+----------------------+---------------+----------------------------+
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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
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.
5. Acknowledgements
The authors thank Hiroki Sato and Masakazu Asama,who made BSD&CentOS
patch.
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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
[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/>.
[Linux 2.6.33]
""sit: 6rd (IPv6 Rapid Deployment) Support."",
<http://kernelnewbies.org/Linux_2_6_33>.
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[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.
[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.
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.--.
_(. `)
_( 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 |
+-----------------+---------------+-------------+
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 |
+-----------+--------------+-------------------------+
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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"
# 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"
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# 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
-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"
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# 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
# make install
-install manual
# cd /usr/src/share/man/
# make
# make install
-modify "/etc/rc.conf"
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# 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 |
+-------------------+---------------+
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
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
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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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