One document matched: draft-mickles-v6ops-isp-analysis-00.txt
INTERNET DRAFT Cleve Mickles(Co-Author/Editor)
Document: draft-mickles-v6ops-isp-analysis-00.txt AOL Time Warner
Expires: Aug 2003 February 2003
Transition Analysis for ISP Networks
Status of this Memo
This document is an Internet-Draft and is subject to all
Provisions of Section 10 of RFC2026. Internet-Drafts are working
documents of the Internet Engineering Task Force (IETF), its
areas, and its working groups. Note that other groups may also
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It is inappropriate to use Internet-Drafts as reference material
or to cite them other than as "work in progress."
The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt
The list of Internet-Draft Shadow Directories can be accessed at
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Abstract
This document provides analysis of how to transition the different
types of Internet Service Provider (ISP) networks to IPv6. It
will provide design recommendations which may be followed to
successfully deploy IPv6 services on a network that began as an
IPv4 network. This is the companion document to
draft-mickles-v6ops-isp-scenarios-04.txt which provides detailed
background information on all scenarios.
mail list for the design team: IPV6@LISTSERV.SUP.AOL.COM
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Table of Contents
1. Introduction................................................3
2. Scope of the document.......................................3
3. Core/Backbone Networks......................................4
3.1 IPv6 Routing Considerations..........................4
3.2 IPv6 Peering Considerations..........................5
3.3 IPv6 Transition Mechanisms...........................5
3.4 Security Considerations..............................6
3.5 Network Management...................................6
4. Broadband HFC/Coax Networks...............................7
4.1 IPv6 Routing Considerations..........................7
4.2 IPv6 Transition Mechanisms...........................7
4.3 Security Considerations..............................7
4.4 Network Management...................................7
5. Broadband DSL Networks.....................................8
5.1 IPv6 Routing Considerations..........................8
5.2 IPv6 Transition Mechanisms...........................8
5.3 Security Considerations..............................8
5.4 Network Management...................................8
6. Narrowband Dialup Networks.................................9
6.1 IPv6 Routing Considerations..........................9
6.2 IPv6 Transition Mechanisms..........................10
6.3 Security Considerations.............................10
6.4 Network Management..................................10
7. Public Wireless LAN.......................................11
7.1 IPv6 Routing Considerations.........................11
7.2 IPv6 Transition Mechanisms..........................11
7.3 Security Considerations.............................11
7.4 Network Management..................................11
8. Broadband Ethernet .......................................12
8.1 IPv6 Routing Considerations.........................12
8.2 IPv6 Transition Mechanisms..........................12
8.3 Security Considerations.............................12
8.4 Network Management..................................12
9. Internet Exchange Point...................................13
9.1 IPv6 Routing Considerations.........................13
9.2 IPv6 Transition Mechanisms..........................13
9.3 Security Considerations.............................13
9.4 Network Management..................................13
10.0 Security Considerations...................................14
11.0 Network Management Considerations.........................14
Acknowledgements..................................................14
References........................................................14
Terminology.......................................................14
Author's Addresses................................................15
Copyright
(C) The Internet Society (2003). All Rights Reserved.
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1. Introduction
This document will provide analysis and recommendations for
ISPs to use in transitioning their existing IPv4 networks to
IPv6. It will show how existing mechanisms can be used to enable
IPv6 capabilities over IP networking components and highlight any
known challenges that may arise during a network transition.
2. Scope of the document
The scope of this document is to cover the major topics ISPs must
consider in transitioning their IP networks to IPv6. It is not
meant to address every detail provided in the scenario document,
but will highlight those details which are most important to the
transition.
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3. Core/Backbone Networks
Transition to IPv6 in the Core network can be done in multiple
ways. The mechanisms discussed below are well known and the
discussion will be scoped based on the general topology below
in figure 3.1
Trunks to remote sites
^ ^
| |
/ /
/ /
/\/ /
/ /\/
/ /
____/____ ____/____
| | | |
| CORE1 | | CORE2 |
|_________| |_________|
____________/ | \ | | |
/ | \ | | |
/ +===========|===\=========+ | |
| / | +=\==========+ |
___|_/_ ___|_/_ \ _____|_
| | | | \____| |
| BDR1 | | BDR2 | | BDR(n)|
|_______| |_______| |_______|\
| | | \
| | | \
| | | \_Peering( Direct & IX )
| | |
___|___ ___|__ ___|___
| | | | | |
| CPE1 | | CPE2 | | CPE(n)|
|_______| |______| |_______|
Figure 3.1
3.1 IPv6 Routing Considerations
In this section we will discuss considerations for the IPv6 in the
internal network as well as the external networking issues.
Since IPv4 exists in the Core IGP, IPv6 capabilities must be added
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while maintaining IPv4 reachability. In essence two IGP protocols
will exist in one routing domain. This mode is generally referred
to as dual-stack mode or "ships in the night" mode. This is not
an entirely new function of routers since running multiple routing
protocols on routers has been a fairly common practice. The
limitations for this practice include CPU power and memory.
To add IPv6 capability to the core network, IPv6 routes must be
present in the IGP. The choices of IGP for IPv6 networking
include ISIS and RIPv2. Ripv2 is the simplest solution. ISIS has
the advantage of being able to carry both IPv4 and IPv6 routes in
one IGP. OSPFv3 is a potential solution but is not currently
available and similar to RIPv2 in that it is not backward
compatible with OSPFv1 which supports IPv4 routes.
For networks which use OSPF as its IGP for IPv4 routes, the
recommendation is to continue carrying IPv4 routes in OSPFv1 and
configure IPv6 routes in ISIS.
For networks which use ISIS, the recommendation is to add IPv6
routes to the existing IGP and run IPv4 and IPv6 integrated within
ISIS.
As the IPv6 network grows, there will exist routers which are only
reachable via IPv6.
3.2 IPv6 Peering Considerations
Generally peering is done on border routers. The two choices for
IPv6 peering include deploying a separate border router for
external IPv6 peering or converting existing IPv4 peering routers
to support IPv6 and IPv4 peering.
In both cases the border routers will exchange IPv6 reachability
information using its IGP.
To exchange IPv6 traffic over an EGP boundary, the routing
protocol of choice remains BGP. The EGP boundary can be
established using either physical circuits or tunneled circuits
which are discussed below. The routing table for IPv6 routes is
separate from the table for Ipv4 routes.
3.3 IPv6 Transition Mechanisms
Once basic decisions about deploying IPv6 services have been
determined how to establish connectivity between IPv6 nodes is the
next step. Since the transition assumes an IPv4 network exists,
there will be transitional nodes which operate in dual stack mode.
There are two choices that may be used to inteconnect IPv6
capable nodes. The first is to use physical links between nodes.
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This has been standard procedure in networking. Point-to-point or
LAN media may be used to establish connectivity and IPv6
addressing is configured over the link. The second choice is to
use "IPv4 over IPv4" tunneling mechanisms to route IPv6 traffic
over IPv4 networks.
3.4 Network Management
Since NM systems are used to monitor and configure networks, the
ability for NM systems to manage IPv6 capable routers must be
maintained. While NM systems will reach dual stack routers over
the IPv4 path, there will be routers which are only reacheable via
IPv6 and therefore NM systems must have an IPv6 presence to manage
those devices
3.5 Security Considerations
Route filtering techniques should continue to be done for IPv6.
IPv6 networks are open to hacking attempts just as IPv4 networks,
but the number of potential devices on a network make random port
scaning less effective.
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4. Broadband HFC/Coax Networks
This section describes the infrastructure that exists in today's
HFC cable networks that support cable modem services to the home.
Since many cable providers are regional they generally have used
the backbone ISP networks for transit IP services beyond their
region.
+-----------+
| |
| |
/-----+ | +--------+
WAN <------+ CMTS |<========>| Modem |<===> CPE
\-----+ | Cable +--------+ |
| | | Network |
| | | |
| +-----------+ |
| |
+-------------------+------------------+
|
"Transparent IP Traffic Through the System"
Figure 4.2.2
4.1 IPv6 Routing Considerations
4.2 IPv6 Transition Mechanisms
4.2.1 Dual Stack Mode
4.2.2 Tunneling
4.2.3 Physical
4.3 Network Management
4.4 Security Considerations
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5. Broadband DSL Networks
This section describes the infrastructure that exists in todays
High Speed DSL Networks.
Customer Premises | Network Access Provider | Network Service Provider
CP NAP NSP
+-----+ +-----+ +-----+
|Hosts|--| DSL +-------+DSLAM|
+-----+ |Modem| | +----+
+-----+ +-----+ |
|
+-----+ +------+ | +-----+ +-------+
|Hosts|--|Router| +--+ BAS +----+ ISP | ISP
+-----+ +--+---+ +--+ | | Edge +===> Network
| | +-----+ | Router|
+--+--+ | +-------+
| DSL +---+ |
|Modem| | |
+-----+ | |
| +-----+ |
+-----+ +------+ +---+DSLAM+----+
|Hosts|--|Router| +---+ |
+-----+ +--+---+ | +-----+
| |
+--+--+ |
| DSL +---+
|Modem|
+-----+
Figure 5.1
5.1 IPv6 Routing Considerations
5.2 IPv6 Transition Mechanisms
5.2.1 Dual Stack Mode
5.2.2 Tunneling
5.3 Network Management
5.4 Security Considerations
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6. Narrowband Dialup Networks
Transitioning the dial up ISP to IPv6 is somewhat straight forward
since the major network devices in this model reside on a single
LAN.
+-----+ +------+ +------+
|Hosts|--| 56K +-------+Modem | +----------+
+-----+ |Modem | |Bank +----------+ ISP 1 | NSP 1
+------+ +------+ | Edge +=====> Network
| | | Router |
| | +----------+
| |
| | +----------+
+-------+ +----------+ ISP 2 | NSP 2
|Radius | | | Edge +=====> Network
|Server | | | Router |
+-------+ | +----------+
|
| +----------+
+----------+ ISP 3 | NSP 3
| Edge +=====> Network
| Router |
+----------+
Figure 6.1
6.1 IPv6 Routing Considerations
To establish IPv6 connectivity in the dial up environment, the
devices between the end user host and NSP Network router must be
IPv6 capable. The ISP edge router must be a dual-stack router.
The ISP edge router should have an IPv6 default route for global
IPv6 reachability. This can be accomplished via the existing
physical circuit to the NSP router if the NSP supports IPv6 or to
a separate NSP' which supports IPv6. An additional alternative is
for the ISP router to tunnel IPv6 traffic over IPv4 to an IPv6
router with global IPv6 reachability.
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6.2 IPv6 Transition Mechanisms
In the dial up ISP environment the devices between the ISP router
and host appear to reside on the same LAN. Therefore the devices
on the LAN must support IPv6.
6.3 Network Management
Since NM systems are used to monitor and configure networks, the
ability for NM systems to manage IPv6 capable devices must be
maintained. While NM systems will reach dual stack devices over
the IPv4 path, there will be devices which are only reacheable via
IPv6 and therefore NM systems must have an IPv6 presence to manage
those devices.
6.4 Security Considerations
Route filtering techniques should continue to be done for IPv6.
IPv6 networks are open to hacking attempts just as IPv4 networks,
but the number of potential devices on a network make random port
scaning less effective.
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7. Public Wireless LAN
This section describes the infrastructure that exists in today's
public wireless LAN services.
+-------+
| AAA |
| Radius|
| TACACS|
'---' +-------+
( ) |
+-----+ (Wireless) +----+ /------------\ +-------+
|Hosts+--( LAN )---| AP |----| Underlying \--- | ISP |=>Core
+-----+ ( ) +----+ \ technology | | Edge |
( ) \-----------/ | Router|
'---' +-------+
Figure 7.1.1. Physical architecture of WLAN model.
7.1 IPv6 Routing Considerations
7.2 IPv6 Transition Mechanisms
7.2.1 Dual Stack Mode
7.2.2 Tunneling
7.3 Network Management
7.4 Security Considerations
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8.0 Broadband Ethernet
This section provides recommendations on how to transition
Ethernet based residential access networks to IPv6.
8.1 IPv6 Routing Considerations
8.2 IPv6 Transition Mechanisms
8.2.1 Dual Stack Mode
8.2.2 Tunneling
8.3 Network Management
8.4 Security Considerations
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9.0 Internet Exchange (IX)
This section provides recommendations on how to transition IPv4
Internet exchanges (IX) to IPv6 exchanges.
______________
____________ +----+ / \
/ \ / | +-( LHP2 router )
( LHP1 router )+ +--+----+ / \______________/
\____________/ | |----+
+---| L2 SW |
______________ / | |-+ ______________
/ \+ +---+---+ \ / \
( LHP3 router ) | +( LHP4 router )
\______________/ | \______________/
+---+----+
| | ____________
| IX | / \
| router +------(IX subscriber )
| | \____________/
+--------+
Figure 9.1
9.1 IPv6 Routing Considerations
9.2 IPv6 Transition Mechanisms
9.2.1 Dual Stack Mode
9.2.2 Tunneling
9.3 Network Management
9.4 Security Considerations
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10. SECURITY CONSIDERATIONS
Security concerns will be described within the context of each
scenario. After the various scenarios are documented, a
summarized section including all of the security considerations
may be provided.
11. NETWORK MANAGEMENT CONSIDERATIONS
Network Management concerns will be described within the context
of each scenario. After the various scenarios are documented, a
summarized section including all of the Network Management
considerations may be provided.
ACKNOWLEDGEMENTS
[1] The comments from the V6OPS working group are appreciated.
REFERENCES
[ISP Scenarios] Mickles, C., et al: "Transition Scenarios
for ISP Networks", February 2003,
draft-mickles-v6ops-isp-scenario-04.txt, work in progress.
[3gpp analysis] Wiljakka, J., et al: "Analysis on IPv6
Transition in 3GPP Networks", January 2003,
draft-ietf-v6ops-3gpp-analysis-01.txt, work in progress.
[Unman Scenarios] Huitema, C., et al: "Unmanaged Networks
IPv6 Transition Scenarios", January 2003,
draft-ietf-v6ops-unman-scenarios-00.txt, work in progress.
TERMS AND ACRONYMS
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Author's Addresses
Vladimir Ksinant
6Wind
1 place Charles de Gaulle - 78180 Phone: +33139309236
Montigny Le Bretonneux - France Email:vladimir.ksinant@6wind.com
Jae-Hwoon Lee
Dongguk Univ.
26, 3 Pil-Dong, Chung-gu, Phone: +82 2 2260 3849
Seoul 100-715, Korea Email: jaehwoon@dgu.ac.kr
Myung-Ki Shin
ETRI PEC
161 Kajong-Dong, Yusong-Gu, Phone: +82 42 860 4847
Taejon 305-350, Korea Email: mkshin@pec.etri.re.kr
Aidan Williams
Motorola Australian Research Centre
Locked Bag 5028 Phone: +61 2 9666 0500
Botany, NSW 1455 Email: Aidan.Williams@motorola.com
Australia
URI: http://www.motorola.com.au/marc/
Alain Baudot
France Telecom R&D
42, rue des coutures Phone: +33 2.31.75.94.27
BP 6243 Email: alain.baudot@rd.francetelecom.com
14066 Caen, FRANCE
Mikael Lind
Telia Research
Vitsandsgatan 9B
123 86 Farsta Phone: +46 70 2406140
Sweden Email: Mikael.e.lind@telia.se
Cleveland Mickles
America Online, Inc (owned by AOL Time Warner)
12100 Sunrise Valley Drive. Phone: +1 703-265-5618
Reston, VA 20191, USA Email: micklesc@aol.net
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