IPv6 Operations T. Chown
Internet-Draft University of Southampton
Expires: April 25, 2005 October 25, 2004
IPv6 Campus Transition Scenario Description and Analysis
draft-chown-v6ops-campus-transition-01
Status of this Memo
By submitting this Internet-Draft, I certify that any applicable
patent or other IPR claims of which I am aware have been disclosed,
and any of which I become aware will be disclosed, in accordance with
RFC 3668.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as
Internet-Drafts.
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."
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
http://www.ietf.org/shadow.html.
This Internet-Draft will expire on April 25, 2005.
Copyright Notice
Copyright (C) The Internet Society (2004). All Rights Reserved.
Abstract
In this document we consider and analyse the specific scenario of
IPv6 transition and deployment in a large department of a university
campus network. The department is large enough to operate its own
instances of all the conventional university services including (for
example) web, DNS, email, filestore, interactive logins, and remote
and wireless access. The scenario is a dual-stack one, i.e.
transition to IPv6 means deploying IPv6 in the first instance
alongside IPv4. This analysis will both identify the available (and
still missing) components for IPv6 transition, and also test the
applicability of the recently completed IPv6 Enterprise Network
Chown Expires April 25, 2005 [Page 1]
Internet-Draft IPv6 Campus Transition October 2004
Scenarios document.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4
1.1 Site Philosphy . . . . . . . . . . . . . . . . . . . . . . 5
2. Discussion of Scenarios Network Infrastructure Components . 5
2.1 Component 1: Enterprise Provider Requirements . . . . . . 5
2.2 Component 2: Enterprise Application Requirements . . . . . 6
2.3 Component 3: Enterprise IT Department Requirements . . . . 7
2.4 Component 4: Enterprise Network Management System . . . . 8
2.5 Component 5: Enterprise Network Interoperation and
Coexistence . . . . . . . . . . . . . . . . . . . . . . . 8
3. Discussion of Network Infrastructure Component
Requirements . . . . . . . . . . . . . . . . . . . . . . . . 9
3.1 DNS . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.2 Routing . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.3 Configuration of Hosts . . . . . . . . . . . . . . . . . . 9
3.4 Security . . . . . . . . . . . . . . . . . . . . . . . . . 10
3.5 Applications . . . . . . . . . . . . . . . . . . . . . . . 10
3.6 Network Management . . . . . . . . . . . . . . . . . . . . 10
3.7 Address Planning . . . . . . . . . . . . . . . . . . . . . 10
3.8 Multicast . . . . . . . . . . . . . . . . . . . . . . . . 10
3.9 Multihoming . . . . . . . . . . . . . . . . . . . . . . . 11
4. Specific Scenario Component Review . . . . . . . . . . . . . 11
4.1 Network Components . . . . . . . . . . . . . . . . . . . . 11
4.1.1 Physical connectivity (Layer 2) . . . . . . . . . . . 11
4.1.2 Routing and Logical subnets (Layer 3) . . . . . . . . 11
4.1.3 Firewall . . . . . . . . . . . . . . . . . . . . . . . 11
4.1.4 Intrusion Detection System . . . . . . . . . . . . . . 12
4.1.5 Management . . . . . . . . . . . . . . . . . . . . . . 12
4.1.6 Monitoring . . . . . . . . . . . . . . . . . . . . . . 12
4.1.7 Remote access . . . . . . . . . . . . . . . . . . . . 12
4.1.8 IPv6 External Access . . . . . . . . . . . . . . . . . 12
4.2 Address Allocation Components . . . . . . . . . . . . . . 12
4.2.1 IPv6 network prefix allocation . . . . . . . . . . . . 12
4.2.2 IPv6 Address allocation . . . . . . . . . . . . . . . 13
4.3 Services . . . . . . . . . . . . . . . . . . . . . . . . . 13
4.3.1 Email . . . . . . . . . . . . . . . . . . . . . . . . 13
4.3.2 Web Hosting . . . . . . . . . . . . . . . . . . . . . 13
4.3.3 Databases . . . . . . . . . . . . . . . . . . . . . . 14
4.3.4 Directory Services . . . . . . . . . . . . . . . . . . 14
4.3.5 DNS . . . . . . . . . . . . . . . . . . . . . . . . . 14
4.3.6 PKI . . . . . . . . . . . . . . . . . . . . . . . . . 14
4.3.7 NTP . . . . . . . . . . . . . . . . . . . . . . . . . 14
4.3.8 USENET News . . . . . . . . . . . . . . . . . . . . . 14
4.3.9 Multicast . . . . . . . . . . . . . . . . . . . . . . 14
4.3.10 Remote login . . . . . . . . . . . . . . . . . . . . 15
Chown Expires April 25, 2005 [Page 2]
Internet-Draft IPv6 Campus Transition October 2004
4.3.11 File serving . . . . . . . . . . . . . . . . . . . . 15
4.3.12 Backups . . . . . . . . . . . . . . . . . . . . . . 15
4.4 Host and Device Platforms . . . . . . . . . . . . . . . . 15
4.4.1 Server platforms . . . . . . . . . . . . . . . . . . . 15
4.4.2 Desktop/laptop platforms . . . . . . . . . . . . . . . 15
4.4.3 PDA platforms . . . . . . . . . . . . . . . . . . . . 16
4.5 User Tools . . . . . . . . . . . . . . . . . . . . . . . . 16
4.5.1 Hardware . . . . . . . . . . . . . . . . . . . . . . . 16
4.5.2 Mail Client . . . . . . . . . . . . . . . . . . . . . 16
4.5.3 Web Browser . . . . . . . . . . . . . . . . . . . . . 16
4.5.4 Conferencing systems . . . . . . . . . . . . . . . . . 17
4.5.5 Other collaboration tools . . . . . . . . . . . . . . 17
4.5.6 Usenet news client . . . . . . . . . . . . . . . . . . 17
4.5.7 Host communications . . . . . . . . . . . . . . . . . 17
4.6 Hard-coded address points . . . . . . . . . . . . . . . . 17
5. Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . 19
5.1 Dual-Stack Deployment: Procedure . . . . . . . . . . . . . 19
5.2 Dual-Stack Deployment: Transition toolbox . . . . . . . . 20
5.3 Missing components . . . . . . . . . . . . . . . . . . . . 21
5.3.1 Standards (IETF)-specific . . . . . . . . . . . . . . 21
5.3.2 Vendor or platform-specific . . . . . . . . . . . . . 21
5.3.3 Application-specific . . . . . . . . . . . . . . . . . 21
5.3.4 Other (policy, political,...) . . . . . . . . . . . . 22
5.4 Considerations beyond the Scenarios Document . . . . . . . 22
6. Summary . . . . . . . . . . . . . . . . . . . . . . . . . . 22
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 22
8. Security Considerations . . . . . . . . . . . . . . . . . . 22
9. Informative References . . . . . . . . . . . . . . . . . . . 23
Author's Address . . . . . . . . . . . . . . . . . . . . . . 24
Intellectual Property and Copyright Statements . . . . . . . 25
Chown Expires April 25, 2005 [Page 3]
Internet-Draft IPv6 Campus Transition October 2004
1. Introduction
The scope of the enterprise network transition scenarios is very
large, much more so than that of the other three IPv6 transition
areas under study within the IETF. The IPv6 Enterprise Network
Scenarios [14] have been defined. In this document we present a
specific case study area for IPv6 transition, namely a large
department (1,500 staff and students, over 1,000 hosts) in an
academic campus network. The purpose of this document in its current
form is to both define and analyse the IPv6 transition of such a
network, but also to test the applicability of the IPv6 Enterprise
Network Scenarios document to a specific example.
The work on IPv6 Enterprise Analysis [19] is now underway, and this
campus transition experience is being fed into that analysis.
Our campus study falls under "Scenario 1" of the IPv6 Enterprise
Network Scenarios [14] document, i.e. the campus network is an
existing IPv4 network, where IPv6 is to be deployed in conjunction
with the IPv4 network.
"Scenario 1" has the assumption that the IPv4 network infrastructure
used has an equivalent capability in IPv6. This document will
analyse that assumption. The Scenario also has requirements, i.e.
that the existing IPv4 network infrastructure is not disrupted, and
that IPv6 should be equivalent or better than the network
infrastructure in IPv4. The Scenario also notes that it may also not
be feasible to deploy IPv6 on all parts of the network immediately.
These assumptions and requirements will be discussed later in this
text.
It should also be noted why Scenarios 2 and 3 did not apply to this
campus transition scenario. Scenario 2 talks of specific
applications, but in the campus case we wish to deploy IPv6
pervasively, in wired and wireless networks, as an enabler for
education and research, to encourage new application development.
Scenario 3 focuses on using IPv6 as the basis for most network
communication, but in the campus we already have a significant IPv4
deployment that will be utilised for the foreseeable future (Scenario
3 would perhaps be more appropriate for a greenfield deployment).
This document is very much a work in progress, and thus this first
instance of this document is not intended to be complete or
comprehensive. Some sections are empty at this stage. We make no
claims that this campus scenario is typical, but believe the lessons
leanrt and analysis undertaken may be of wider interest. Feedback is
sought on scope and the required level of detail.
Chown Expires April 25, 2005 [Page 4]
Internet-Draft IPv6 Campus Transition October 2004
1.1 Site Philosphy
The site which is the subject of this study is an IPv4 network with
up to 20 subnets, using a core network infrastructure that combines
switch-router functionality in centralised devices, with switches at
the network edge. The main switching equipment is all VLAN capable.
There are around 1,000 networked nodes, and 1,500 users.
The site wishes to deploy IPv6 dual-stack. Currently, the core
network infrastructure does not support IPv6, and no upgrade is
possible. Thus the infrastructure cannot support IPv6 until the next
procurement cycle. Given the site wishes to deploy IPv6 pervasively
as soon as possible, and interim deployment solution is required.
The goal is to IPv6 enable the network (on the wire) and services
(DNS, SMTP, etc) such that the whole operation is dual-stack. This
will allow in due course IPv6-only devices to be deployed within the
fully IPv6-capable environment. Some network links may become
IPv6-only in the future.
2. Discussion of Scenarios Network Infrastructure Components
In this section, we look at the issues raised by following the
Scenarios Network Infrastructure Components of the IPv6 Enterprise
Network Scenarios [14] document, section 3.2.
2.1 Component 1: Enterprise Provider Requirements
The answers to the questions posed in this section of the IPv6
Enterprise Network Scenarios document are as follows:
o There is external access to/from the campus network, regional MAN
and National Research Network beyond.
o There are needs for access by remote staff, student and
researchers.
o It is a single site, with four buildings.
o There are no leased lines or wide-area VPNs between remote
buildings.
o The department has 12 IPv4 Class C's, the campus has a Class B,
independent from its provider (assigned prior to use of CIDR).
o The IPv4 and IPv6 provider is the National Research and Education
Network (JANET in the UK). JANET provides a /48 prefix for the
university. The university offers a /52 prefix for the
department.
Chown Expires April 25, 2005 [Page 5]
Internet-Draft IPv6 Campus Transition October 2004
o The university and department make their own prefix allocations
for subnets.
o There is no multihoming, and thus no multihomed clients.
o The only IPv6 service offered by the provider to date is a 6to4
[4] relay.
o There is no exteral IPv6 routing protocol needed due to the use of
static route configuration.
o There is no external data centre.
o IPv6 runs over the same access links to campus (the JANET backbone
uses true dual stack, the regional MAN uses 6PE [15]. On campus,
the IPv4 traffic to the department is received through a Nokia
IP740 firewall, the IPv6 traffic is received through a BSD
firewall. Thus the access links into the department for IPv4 and
IPv6 are different, though the goal is to make them the same.
2.2 Component 2: Enterprise Application Requirements
Answers to the next IPv6 Enterprise Network Scenarios section are as
follows:
o The application inventory is discussed in the specific component
review in the next section.
o We expect the first applications to be moved will be the support
services, including DNS. The first applications should be the
common IPv4 applications, e.g. web, remote login and email, such
that IPv6 offers as least an equivalent service to IPv4 for the
important applications.
o The academic environment has a good mix of open source and
commercial software, predominantly either Microsoft or Linux, but
with a growing number of Mac OS/X users. Specific platforms are
reviewed in the component review in the next main section. Most
open source applications have been upgraded to allow IPv6
operation; others can be upgraded given time.
o The general goal is for applications to support both IPv4 or IPv6
operation, i.e. to be IP agnostic.
o There is no use of NAT in the department's network. Home users,
or users access into the network remotely from certain locations,
may experience NAT at their client side.
Chown Expires April 25, 2005 [Page 6]
Internet-Draft IPv6 Campus Transition October 2004
o NAT issues are relevant from the end-to-end perspective, for
establishment of end-to-end security where desired, and in
relation to IPv6 transition (remote access) mathods that may be
run through NATs.
o There is a mix of internal and external applications. Where
limitations occur, it is mainly by policy not technology, e.g. as
implemented in firewall restrictions.
2.3 Component 3: Enterprise IT Department Requirements
Here we list responses to the next IPv6 Enterprise Network Scenarios
section on IT Department Requirements:
o Ownership and support is all in-house.
o Remote VPNs are supported.
o No inter-site networking is required.
o No network mobility support is needed at this point, though we
expect to use Mobile IPv6 between the department network and a
local community wireless network.
o The IPv6 address plan for the department requires a /52 prefix.
o There is no detailed asset database, though one is being built.
o There are no geographically separate sites.
o The internal IPv4 address assignment mechanism is DHCP for
clients, with manual configuration for servers. We thus expect to
use DHCPv6 for at least some IPv6 clients.
o Internal IPv4 routing is static or uses RIP. We thus expect to
use RIPng internally.
o We expect our IPv6 network management policy to be very similar to
that for IPv4.
o There is no QoS provision at present, largely due to the ample
campus bandwidth (1Gbit/s uplink).
o Security is applied through many technologies implementing our
policies, e.g. firewall, email scanning, wireless LAN access
controls. We expect similar policies for IPv6, but need to
analyse differences.
Chown Expires April 25, 2005 [Page 7]
Internet-Draft IPv6 Campus Transition October 2004
o Training will be done in-house.
o The impacted software components are discussed in the next main
section. Not all functions are upgradeable to IPv6; those that
are not are discussed in the analysis section. Some are, e.g.
use of OpenLDAP in place of MS Active Directory.
o The impacted hardware components are discussed in the next main
section. Not all hardware is upgradeable, e.g. network printers.
There are no load balancing systems in use. There are wireless
LAN hosts in the network that are mobile, but currently the
wireless network is a flat IPv4 subnet. There may be nodes moving
to external wireless networks (the local community wireless
network.
2.4 Component 4: Enterprise Network Management System
The responses to the next IPv6 Enterprise Network Scenarios section
are as follows:
o No performance management is required.
o There are a number of network management and monitoring tools in
use, which will need to be used in a dual stack or IPv6 mode, e.g.
the nocol availability monitring tools, and SNMP-based management.
o The configuration management may include use of tools to configure
services including DNS and email.
o No policy management and enforcement tools are required.
o No detailed security management is required, though we expect to
manage the implementations including firewalls and intrusion
detection.
o We may need to manage the deployed transition tools and
mechanisms.
o We need to analyse the considerations IPv6 creates for network
management, e.g. use (or not) of RFC3041 privacy addresses.
2.5 Component 5: Enterprise Network Interoperation and Coexistence
Answers to the final IPv6 Enterprise Network Scenarios section on
Coexistence are as follows:
Chown Expires April 25, 2005 [Page 8]
Internet-Draft IPv6 Campus Transition October 2004
o The platforms that are required to be IPv6 capable are listed in
the next main section.
o There is only one network ingress and egress point to the site
that needs to be IPv6 capable; this is a Gigabit Ethernet
interface.
o The required transition mechanisms are discussed in the analysis
section. We expect to mainly use the VLAN [8] mechanism for
internal IPv6 transport, with a parallel IPv6 routing
infrastructure based on BSD routers, until the core infrastructure
is able to support IPv6 (via upgrade or a new procurement).
o The transition to IPv6 will be enabled on the wire first, enabling
clients, with a phased introduction of service capability, as
discussed below in the analysis section.
o The preferred mechanism for interoperation with legacy nodes is to
use dual-stack and thus IPv4 to communicate to IPv4 nodes and IPv6
to communicate to IPv6 nodes. We have not identified any
in-house, non-upgradeable legacy applications.
3. Discussion of Network Infrastructure Component Requirements
In this section, we discuss the network infrastructure component
requirements raised in the IPv6 Enterprise Network Scenarios [14]
document, in section 4.
3.1 DNS
BIND9 is used for our three internal name servers. The servers will
be made dual stack, to be available for IPv6 transport for local
dual-stack or IPv6-only nodes. The three servers will each be listed
with AAAA records, and AAAA glue added.
3.2 Routing
Internal routing is either statically configured or uses RIP. We
thus expect to use RIPng for internal IPv6 routing. The external
routing is statically configured for IPv4, and thus is likely to be
statically configured for IPv6.
3.3 Configuration of Hosts
IPv4 clients use DHCP for address and other configuration options.
We expect to use Dynamic Host Configuration Protocol for IPv6
Chown Expires April 25, 2005 [Page 9]
Internet-Draft IPv6 Campus Transition October 2004
(DHCPv6) [5] for IPv6 clients. This will require analysis of the
IPv4 and IPv6 Dual-Stack Issues for DHCPv6 [11]. We expect some
clients, especially in wireless LANs, to use IPv6 Stateless
Autoconfiguration [1], and these nodes will need support for
Stateless Dynamic Host Configuration Protocol (DHCP) Service for IPv6
[6] for other configuration options, including the IPv6 address of a
local DNS resolver.
Although IPv6 offers Stateless Autoconfiguration, it is expected that
the managed environment will continue, driven from the asset
database, for some time. Thus DHCPv6 is required. Use of Stateless
Autoconfiguration implies a requirement for dynamic DNS updates for
such nodes. It is not yet decided how to apply or enforce that plan;
it may certainly be flexible with time.
3.4 Security
We need to identify new IPv6 related security considerations, and
those associated with transition mechanisms [16]. Site policies may
need to be updated as a result.
3.5 Applications
The Application Aspects of IPv6 Transition [13] document describes
best porting practice for applications. There should also be
consideration for any required application proxies.
3.6 Network Management
The network management and monitoring systems will need to embrace
IPv6, and any transition mechanisms used to deploy IPv6. Monitoring
includes usage tracking (e.g. via MRTG) and availability monitoring
(e.g. via nocol).
3.7 Address Planning
The department receives 12 Class C prefixes for IPv4 use, and uses
only globally routable addresses internally. The IPv4 address space
for the campus was obtained prior to CIDR, but the IPv6 address space
is allocated from the UK National Research Network (JANET) address
space under 2001:0630::/32. The university receives a /48 prefix,
which is 2001:0630:d0::/48. The department has a /52 allocation
within this block of 2001:0630:d0:0:/52.
3.8 Multicast
IPv4 multicast is used for a number of applications, including the
AccessGrid. Connectivity is provided via the local campus and
Chown Expires April 25, 2005 [Page 10]
Internet-Draft IPv6 Campus Transition October 2004
regional network. We expect to use both IPv6 ASM (i.e. PIM-SM), and
may seek to make use of the Embedding the Address of RP in IPv6
Multicast Address [12] technique. For briding between IPv4 and IPv6
multicast, we believe an IPv4 - IPv6 multicast gateway [17] may prove
valuable. Finally, we expect to make use of source specific
multicast (SSM) more heavily in IPv6, bringing IPv6 and SSM together
in one deployment cycle.
3.9 Multihoming
The site is not multihomed.
4. Specific Scenario Component Review
Here we describe specific technology in use now in the department.
Later in this section we discuss any items not included in the above
section, i.e. those not explicitly mentioned in the IPv6 Enterprise
Network Scenarios document. In the next main section we analyse
these for missing technologies, as a form of gap analysis.
4.1 Network Components
4.1.1 Physical connectivity (Layer 2)
o Switched Ethernet
o Gigabit Ethernet
o Wireless networking (802.11b)
4.1.2 Routing and Logical subnets (Layer 3)
The hybrid Layer 2/3 routing equipment has approximately 20 internal
IPv4 subnets (in effect, routed VLANs). There is no specific
internal routing protocol used. There is a static route via the site
firewall to the main upstream provider (academic) running at 1Gbit/s.
4.1.3 Firewall
The firewall is currently CheckPoint Firewall-1 running on a Sun
Solaris platform, just migrating to a Nokia IP740 hardware platform.
There is one internal facing interface, one external facing
interface, and two .DMZ. interfaces, one for wired hosts and one for
the Wireless LAN provision.
Chown Expires April 25, 2005 [Page 11]
Internet-Draft IPv6 Campus Transition October 2004
4.1.4 Intrusion Detection System
Snort is used locally for IPv4 IDS. There is some IPv6 functionality
in Snort. The precise requirements of an IPv6 IDS need to be
understood.
4.1.5 Management
Some network management is performend by SNMP; there is no specific
package for this. There is a greater emphasis on monitoring than
explictly in management.
4.1.6 Monitoring
A number of tools are used, to monitor network usage as well as
systems availability, e.g. nocol, nagios and MRTG. The IBM AWM tool
is used for network testing, along with iperf, rude and crude.
4.1.7 Remote access
o Livingston Portmaster 56K/ISDN dialup
o RADIUS server
o (Microsoft) VPN server
4.1.8 IPv6 External Access
o IPv6 connectivity comes via 6PE from our regional network.
4.2 Address Allocation Components
The department receives its IPv4 and IPv6 address allocations from
the University. For IPv4, the University has a Class B allocation
which is not aggregated under the JANET NREN. For IPv6, the
University receives its allocation from JANET.
4.2.1 IPv6 network prefix allocation
For IPv6, JANET has the prefix 2001:630::/32 from RIPE-NCC, as the
national academic ISP in the UK. The University has been allocated
2001:630:d0::/48 by JANET. The department transitioning will be
allocated a /52 size prefix under 2001:630:d0::/48, i.e.
2001:630:d0:0::/52.
In the initial deployment, we expect that IPv4 and IPv6 subnets will
Chown Expires April 25, 2005 [Page 12]
Internet-Draft IPv6 Campus Transition October 2004
be congruent (and share the same VLANs). The advantage for IPv6 is
that subnets will not need to be resized to conserve or efficiently
utilise address space as is the case currently for IPv4 (as subnet
host counts rise and fall for administrative or research group
growth/decline reasons).
4.2.2 IPv6 Address allocation
It is expected that the network devices will use a combination of
address allocation mechanisms:
o Manually configured addresses (in some servers)
o Stateful DHCPv6 (probably in fixed, wired devices and some
servers)
o Stateless address autoconfiguration (probably in wireless and
mobile devices)
o RFC3041 privacy addresses (in some client devices)
For devices using stateless or RFC3041 mechanisms, a Stateless DHCPv6
server will be required for other (non-address) configuration
options, e.g. DNS and NTP servers.
4.3 Services
4.3.1 Email
There are three MX hosts for inbound email, and two main internal
mail servers. Sendmail is the MTA. POP and IMAP (and their secure
versions) are used for mail access, using the UW-IMAP open source
code. There is an MS Exchange server used by up to 100 users
(generally those wanting shared access to mail spools, e.g.
professors and secretaries). MailScanner is used for anti-spam/
anti-virus. This uses external services including various RBLs for
part of its spam checking. Successful reverse DNS lookup is required
for sendmail to accept internal SMTP connections for delivery.
4.3.2 Web Hosting
Web content hosting is provided either with Apache 1.3.x (open
source) or Microsoft IIS 5.0. Common components used to build
systems with are MySQL, PHP 4 and Perl 5; these enable local tools
such as Wikis to be run.
Chown Expires April 25, 2005 [Page 13]
Internet-Draft IPv6 Campus Transition October 2004
4.3.3 Databases
All database systems are presented via a web interface, including the
financial systems. In some cases, e.g. student records, ODBC-like
access is required/used in to/out from the department systems to the
campus systems. Databases include: finance records, people, projects
and publications (offered using ePrints).
4.3.4 Directory Services
The following are used:
o NIS (6 servers, all Solaris)
o LDAP
o Active Directory
o RADIUS
4.3.5 DNS
The three DNS servers have recently been upgraded to BIND9. A DNS
secondary is held at another UK university site.
4.3.6 PKI
The department has at least 10 SSL certificates from Thawte,
including Web-signing certificates. No personal certificates are
supported by the department (though users may have their own).
4.3.7 NTP
The JANET NREN offers a stratum 0 NTP server. The department also
has a GPS-based NTP server built-in to its own RIPE NCC test traffic
server.
4.3.8 USENET News
The news feed is delivered using dnews.
4.3.9 Multicast
There is PIM-SM IPv4 multicast via a dedicated Cisco 7206 router.
This supports applications including the IPv4 AccessGrid conferencing
system. A number of bugs in the existing IPv4 equipment prevent
heavy use of IPv4 Multicast within the department network (thus an
Chown Expires April 25, 2005 [Page 14]
Internet-Draft IPv6 Campus Transition October 2004
IPv6 Multicast solution is highly desirable). An IPv4 Multicast
beacon is used for monitoring Multicast.
4.3.10 Remote login
Remote login access is offered via ssh, with sftp for file transfer.
Remote use of telnet and ftp is denied by the firewall.
4.3.11 File serving
The main file servers are SGI systems, hosting large (multi-TB)
standalone RAID arrays. The files are offered via NFS and Samba to
client systems. The content distribution server is hosted on such a
system (e.g. containing MS software licenced under the Campus
Agreement).
4.3.12 Backups
Backups are run over SSH, which is IPv6-enabled. A site using a
proprietary rempte backup solution may not yet have IPv6 capability.
4.4 Host and Device Platforms
4.4.1 Server platforms
These include:
o Windows 2003 server
o Windows 2000 server
o Windows NT
o Solaris 8
o Solaris 9
o RedHat Linux
o SGI Origin 300 (Irix 6.5.x)
4.4.2 Desktop/laptop platforms
These include:
o Windows 98, 2000, ME, XP
Chown Expires April 25, 2005 [Page 15]
Internet-Draft IPv6 Campus Transition October 2004
o Linux (various flavours)
o MacOS/X
o BSD (various flavours)
4.4.3 PDA platforms
These include:
o Windows CE/.NET, Pocket PC
o PalmOS
o Familiar Linux on iPaQ
o Zaurus (Linux)
4.5 User Tools
These are non-exhaustive but representative application/platform
lists
4.5.1 Hardware
o Networked printers
o Networked webcams
4.5.2 Mail Client
o Outlook (various versions)
o Eudora
o Mutt
o Pine
4.5.3 Web Browser
o MS Internet Explorer
o Mozilla
Chown Expires April 25, 2005 [Page 16]
Internet-Draft IPv6 Campus Transition October 2004
o Safari
o Opera
4.5.4 Conferencing systems
o AccessGrid
o A dedicated H.323 system
o MS Netmeeting
4.5.5 Other collaboration tools
o IRC
o Jabber
o MSN Messenger
o cvs
4.5.6 Usenet news client
o nn
o Mozilla
4.5.7 Host communications
o X11
o VNC
o PC Anywhere
4.6 Hard-coded address points
Usage of IPv4 hard-coded addresses is interesting for at least two
reasons. One is that it illustrates where IPv6 hard-coded addresses
may appear, and thus secondly it is useful to analyse which
hard-coded addresses may be barriers to smooth IPv6 renumbering. A
procedure for renumbering has been described in Procedures for
Chown Expires April 25, 2005 [Page 17]
Internet-Draft IPv6 Campus Transition October 2004
Renumbering an IPv6 Network without a Flag Day [7]. A non-exhaustive
list of instances of such addresses includes:
o Provider based prefix(es)
o Names resolved to IP addresses in firewall at startup time
o IP addresses in remote firewalls allowing access to remote
services
o IP-based authentication in remote systems allowing access to
online bibliographic resources
o IP address of both tunnel end points for IPv6 in IPv4 tunnel
o Hard-coded IP subnet configuration information
o IP addresses for static route targets
o Blocked SMTP server IP list (spam sources)
o Web .htaccess and remote access controls
o Apache .Listen. directive on given IP address
o Configured multicast rendezvous point
o TCP wrapper files
o Samba configuration files
o DNS resolv.conf on Unix
o Nocol monitoring tool
o NIS/ypbind via the hosts file
o Some interface configurations
o Unix portmap security masks
o NIS security masks
The author is contributing to work in studying things to think about
in IPv6 renumbering [18], where the above issues will be considered.
Chown Expires April 25, 2005 [Page 18]
Internet-Draft IPv6 Campus Transition October 2004
5. Analysis
We start by noting that our analysis does not include issues relating
to deployment of new IPv6-specific technology, e.g. MIPv6.
The work described in this document is also being fed into the IPv6
Enterprise Analysis [19] document, currently an ongoing work within
the IPv6 Operations WG. The reader is referred in particular to
Section 4 ("Wide-Scale Dual-Stack Deployment") and Section 7
("General issues and applicability for all Scenarios") which were
directly contributed from the work here.
5.1 Dual-Stack Deployment: Procedure
As described in the IPv6 Enterprise Analysis [19] document, the
scenario here is one of wide-scale dual-stack deployment. The plan
for deployment follows the general guidelines of Section 7 of that
document, i.e.:
o Gaining initial connectivity. In our case, the connectivity is
native IPv6 from JANET, via the regional MAN (using 6PE [15]) and
the campus (using a VLAN to carry IPv6 natively).
o Obtaining global IPv6 address space. The campus address space is
a /48 prefix allocated by JANET, under their prefix of 2001:630::/
32.
o Deploying basic network services: DNS, routing, host configuration
support. We are currently using BIND9 for DNS servers, static or
RIPng routing, and SLAAC host configuration until DHCPv6
implementations are available.
o Formulating an IPv6 addressing plan. Our campus has allocated the
department network a /56 prefix that can grow into a /52 prefix,
i.e. the department can create in theory up to 256 IPv6 subnets
initially. However, because the department runs an IPv6 tunnel
broker for remote access, allocations from the /52 will be taken
up early.
o Ensuring IPv6 security. This is a function of site policy, which
needs to be updated for IPv6-specific issues, e.g. privacy
addresses, and implemented, via an IPv6 firewall and other
measures.
o IPv4-IPv6 interworking. As there are not (yet) any IPv6-only
links, interowrking methods are not required. Should IPv6-only
devices be deployed on the dual-stack infrastructure, we
anticipate using proxy tools (web cache, SMTP relay, etc) to
Chown Expires April 25, 2005 [Page 19]
Internet-Draft IPv6 Campus Transition October 2004
support their access to legacy IPv4 services.
o Supporting remote users. These may connect via an IPv4 VPN and
then use an IPv6 connection over that VPN, or use the remote IPv6
services that we operate (a tunnel broker and a 6to4 relay, as
described below).
o Deploying wider IPv6 application, management and service support.
This is an ongoing task, based on the services described in
previous sections.
5.2 Dual-Stack Deployment: Transition toolbox
We are using the following mechanisms in our department transition
plan:
o VLANs [8] to distribute IPv6 connectivity over the existing
non-dual-stack network infrastructure. When dual-stack
infrastructure is available, and the next procurement due, we will
upgrade the core network infrastructure to dual-stack. The VLAN
solution is an interim step;
o An Tunnel broker [3] for remote access;
o A 6to4 [4] relay for remote access. Users can manually configure
the relay's IPv4 address.
We may consider deploying a Teredo [10] relay in due course to
support home users behind NATs, but have no current plans to do so.
We do NOT currently see a requirement for:
o NAT-PT [2], because we are dual-stack with no IPv6-only networks
(yet), and as we introduce such networks, or IPv6-only nodes in
the dual-stack networks, we expect to use application layer
gateways and proxies for legacy IPv4 access;
o ISATAP [20], because we prefer to use a structured internal IPv6
deployment, and are doing so in a pervasive fashion (i.e. not as
a sparse deployment);
o Teredo [10], as our remote users are capable of using other access
methods. However, we may deploy a Teredo relay in due course to
support home users behind NATs if they report problems with using
other access methods.
Chown Expires April 25, 2005 [Page 20]
Internet-Draft IPv6 Campus Transition October 2004
5.3 Missing components
An initial gap analysis for technology highlights the following
missing components.
5.3.1 Standards (IETF)-specific
o No method available to offer reverse IPv6 DNS for sendmail to
verify autoconfiguring hosts (prepopulating a 64 bit subnet space
is a problem, some wildcard method is required).
5.3.2 Vendor or platform-specific
o No IPv6 Layer 3 functionality on the department's current Ethernet
switch/routing equipment (this will be worked around using the
parallel VLAN method, until new IPv6-capable equipment is
deployed);
o Lack of NFS/Samba IPv6 support;
o No IPv6 support for Active Directory;
o Lack of supported IPv6 for Windows 98/2000/ME;
o Lack of supported IPv6 for Irix;
o Lack of supported IPv6 for various PDA platforms;
o Lack of MLDv2 (or MLDv1) snooping in Ethernet switch equipment
(thus IPv6 Multicast will flood subnets);
o No available IPv6-enabled X11 (there is an xfree but it is
encumbered by an unpopular copyright statement that most
distributors find unnacceptable);
o No support for IPv6 hotspot access control via web-redirection
systems;
o Few DHCPv6 server implemntations, very few client implementations.
5.3.3 Application-specific
o Lack of MS Exchange, Outlook or Eudora IPv6 support;
o AccessGrid is IPv4-only (IPv6-enabling work is to be undertaken in
6NET);
Chown Expires April 25, 2005 [Page 21]
Internet-Draft IPv6 Campus Transition October 2004
o Some Apache 2 modules lack Apache 1.3 functionality, hence
migrating is a problem in a small number of cases;
o No IPv6 dnews, so one would have to use inn as a Usenet news
server.
5.3.4 Other (policy, political,...)
o The migration from ip6.int to ip6.arpa is moving slowly.
5.4 Considerations beyond the Scenarios Document
Here we mention issues or scenario components that were not
explicitly listed in the IPv6 Enterprise Network Scenarios document.
Due to the scope, that document could not embrace all details. We
mention here components that other sites may also wish to consider:
o Support for WLAN and other access control. One solution is to use
802.1x which is IP-agnostic as a Layer 2 port control mechanism.
o Consideration for hard-coded addresses.
o ..To be completed..
6. Summary
In this document we will analyse the specific campus transition
scenario for the author's site, and report the analysis for the
benefit of others who may be in a similar scenario, or for whom parts
of the scenario are relevant. The basic IPv6 deployment is doable
now, but there are still missing components that prevent a full
dual-stack deployment.
7. Acknowledgements
Discussions with fellow participants on the 6NET and Euro6IX projects
have been valuable.
8. Security Considerations
There are no specific new considerations from this scenario
description and analysis.
Chown Expires April 25, 2005 [Page 22]
Internet-Draft IPv6 Campus Transition October 2004
9 Informative References
[1] Thomson, S. and T. Narten, "IPv6 Stateless Address
Autoconfiguration", RFC 2462, December 1998.
[2] Tsirtsis, G. and P. Srisuresh, "Network Address Translation -
Protocol Translation (NAT-PT)", RFC 2766, February 2000.
[3] Durand, A., Fasano, P., Guardini, I. and D. Lento, "IPv6 Tunnel
Broker", RFC 3053, January 2001.
[4] Carpenter, B. and K. Moore, "Connection of IPv6 Domains via
IPv4 Clouds", RFC 3056, February 2001.
[5] Droms, R., Bound, J., Volz, B., Lemon, T., Perkins, C. and M.
Carney, "Dynamic Host Configuration Protocol for IPv6
(DHCPv6)", RFC 3315, July 2003.
[6] Droms, R., "Stateless Dynamic Host Configuration Protocol
(DHCP) Service for IPv6", RFC 3736, April 2004.
[7] Baker, F., Lear, E. and R. Droms, "Procedures for Renumbering
an IPv6 Network without a Flag Day",
draft-baker-ipv6-renumber-procedure-01 (work in progress),
October 2003.
[8] Chown, T., "Use of VLANs for IPv4-IPv6 Coexistence in
Enterprise Networks", draft-chown-v6ops-vlan-usage-01 (work in
progress), July 2004.
[9] Chown, T., Venaas, S. and C. Strauf, "IPv4 and IPv6 Dual-Stack
Issues for DHCPv6", draft-chown-dhc-dual-stack-00 (work in
progress), February 2004.
[10] Huitema, C., "Teredo: Tunneling IPv6 over UDP through NATs",
draft-huitema-v6ops-teredo-02 (work in progress), June 2004.
[11] Chown, T., "DHCP: IPv4 and IPv6 Dual-Stack Issues",
draft-ietf-dhc-dual-stack-01 (work in progress), July 2004.
[12] Savola, P. and B. Haberman, "Embedding the Rendezvous Point
(RP) Address in an IPv6 Multicast Address",
draft-ietf-mboned-embeddedrp-07 (work in progress), July 2004.
[13] Shin, M., "Application Aspects of IPv6 Transition",
draft-ietf-v6ops-application-transition-03 (work in progress),
June 2004.
Chown Expires April 25, 2005 [Page 23]
Internet-Draft IPv6 Campus Transition October 2004
[14] Bound, J., "IPv6 Enterprise Network Scenarios",
draft-ietf-v6ops-ent-scenarios-05 (work in progress), July
2004.
[15] Clercq, J., "Connecting IPv6 Islands over IPv4 MPLS using IPv6
Provider Edge Routers (6PE)", draft-ooms-v6ops-bgp-tunnel-03
(work in progress), April 2004.
[16] Savola, P., "IPv6 Transition/Co-existence Security
Considerations", draft-savola-v6ops-security-overview-02 (work
in progress), February 2004.
[17] Venaas, S., "An IPv4 - IPv6 multicast gateway",
draft-venaas-mboned-v4v6mcastgw-00 (work in progress), February
2003.
[18] Chown, T., "Things to think about when Renumbering an IPv6
network", draft-chown-v6ops-renumber-thinkabout-00 (work in
progress), October 2004.
[19] Bound, J., "IPv6 Enterprise Network Analysis",
draft-ietf-v6ops-ent-analysis-00 (work in progress), September
2004.
[20] Templin, F., Gleeson, T., Talwar, M. and D. Thaler, "Intra-Site
Automatic Tunnel Addressing Protocol (ISATAP)",
draft-ietf-ngtrans-isatap-22 (work in progress), May 2004.
Author's Address
Tim Chown
University of Southampton
School of Electronics and Computer Science
Southampton, Hampshire SO17 1BJ
United Kingdom
EMail: tjc@ecs.soton.ac.uk
Chown Expires April 25, 2005 [Page 24]
Internet-Draft IPv6 Campus Transition October 2004
Intellectual Property Statement
The IETF takes no position regarding the validity or scope of any
Intellectual Property Rights or other rights that might be claimed to
pertain to the implementation or use of the technology described in
this document or the extent to which any license under such rights
might or might not be available; nor does it represent that it has
made any independent effort to identify any such rights. Information
on the procedures with respect to rights in RFC documents can be
found in BCP 78 and BCP 79.
Copies of IPR disclosures made to the IETF Secretariat and any
assurances of licenses to be made available, or the result of an
attempt made to obtain a general license or permission for the use of
such proprietary rights by implementers or users of this
specification can be obtained from the IETF on-line IPR repository at
http://www.ietf.org/ipr.
The IETF invites any interested party to bring to its attention any
copyrights, patents or patent applications, or other proprietary
rights that may cover technology that may be required to implement
this standard. Please address the information to the IETF at
ietf-ipr@ietf.org.
Disclaimer of Validity
This document and the information contained herein are provided on an
"AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET
ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED,
INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE
INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Copyright Statement
Copyright (C) The Internet Society (2004). This document is subject
to the rights, licenses and restrictions contained in BCP 78, and
except as set forth therein, the authors retain all their rights.
Acknowledgment
Funding for the RFC Editor function is currently provided by the
Internet Society.
Chown Expires April 25, 2005 [Page 25]