Request for Comments: 4057 Hewlett Packard
Category: Informational June 2005
IPv6 Enterprise Network Scenarios
Status of This Memo
This memo provides information for the Internet community. It does
not specify an Internet standard of any kind. Distribution of this
memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (2005).
Abstract
This document describes the scenarios for IPv6 deployment within
enterprise networks. It defines a small set of basic enterprise
scenarios and includes pertinent questions to allow enterprise
administrators to further refine their deployment scenarios.
Enterprise deployment requirements are discussed in terms of
coexistence with IPv4 nodes, networks and applications, and in terms
of basic network infrastructure requirements for IPv6 deployment.
The scenarios and requirements described in this document will be the
basis for further analysis to determine what coexistence techniques
and mechanisms are needed for enterprise IPv6 deployment. The
results of that analysis will be published in a separate document.
Table of Contents
1. Introduction................................................... 2
2. Terminology.................................................... 3
3. Base Scenarios................................................. 4
3.1. Base Scenarios Defined................................... 4
3.2. Scenarios Network Infrastructure Components.............. 5
3.3. Specific Scenario Examples............................... 8
3.4. Applicability Statement..................................10
4. Network Infrastructure Component Requirements..................10
4.1. DNS......................................................11
4.2. Routing..................................................11
4.3. Configuration of Hosts...................................11
4.4. Security.................................................11
4.5. Applications.............................................12
4.6. Network Management.......................................12
4.7. Address Planning.........................................12
4.8. Multicast................................................12
4.9. Multihoming..............................................12
5. Security Considerations........................................12
6. Normative References...........................................13
Acknowledgements...................................................13
1. Introduction
This document describes the scenarios for IPv6 deployment within
enterprise networks. It defines a small set of basic enterprise
scenarios and includes pertinent questions to allow enterprise
administrators to further refine their deployment scenarios.
Enterprise deployment requirements are discussed in terms of
coexistence with IPv4 nodes, networks and applications, and in terms
of basic network infrastructure requirements for IPv6 deployment.
The scenarios and requirements described in this document will be the
basis for further analysis to determine what coexistence techniques
and mechanisms are needed for enterprise IPv6 deployment. The
results of that analysis will be published in a separate document.
The audience for this document is the enterprise network team
considering deployment of IPv6. The document will be useful for
enterprise teams that will have to determine the IPv6 transition
strategy for their enterprise. It is expected those teams include
members from management, network operations, and engineering. The
scenarios presented provide an example set of cases the enterprise
can use to build an IPv6 network scenario.
To frame the discussion, this document will describe a set of
scenarios each with a network infrastructure. It is impossible to
define every possible enterprise scenario that will apply to IPv6
adoption and transition.
Each enterprise will select the transition that best supports their
business requirements. Any attempt to define a default or one-size-
fits-all transition scenario, simply will not work. This document
does not try to depict the drivers for adoption of IPv6 by an
enterprise.
While it is difficult to quantify all the scenarios for an enterprise
network team to plan for IPv6, it is possible to depict a set of
abstract scenarios that will assist with planning. This document
presents three base scenarios to be used as models by enterprises
defining specific scenarios.
The first scenario assumes the enterprise decides to deploy IPv6 in
conjunction with IPv4. The second scenario assumes the enterprise
decides to deploy IPv6 because of a specific set of applications that
it wants to use over an IPv6 network. The third scenario assumes an
enterprise is building a new network or restructuring an existing
network and decides to deploy IPv6 as the predominant protocol within
the enterprise coexisting with IPv4. This document then briefly
reviews a set of network infrastructure components that must be
analyzed, which are common to most enterprises.
This document then provides three specific scenario examples using
the network infrastructure components to depict the requirements.
These are common enterprise deployment cases to depict the challenges
for the enterprise to transition a network to IPv6.
Next, supporting legacy functions on the network (while the
transition is in process), and the network infrastructure components
requiring analysis by the enterprise are discussed. The
interoperation with legacy functions within the enterprise will be
required for all transition except possibly by a new network that
will be IPv6 from inception. The network infrastructure components
will depict functions in their networks that require consideration
for IPv6 deployment and transition.
Using the scenarios, network infrastructure components, and examples
in this document, an enterprise can define its specific scenario
requirements. Understanding the legacy functions and network
infrastructure components required, the enterprise can determine the
network operations required to deploy IPv6. The tools and mechanisms
to support IPv6 deployment operations will require enterprise
analysis. The analysis to determine the tools and mechanisms to
support the scenarios will be presented in subsequent document(s).
2. Terminology
Enterprise Network - A network that has multiple internal links, one
or more router connections to one or more
Providers, and is actively managed by a network
operations entity.
Provider - An entity that provides services and
connectivity to the Internet or other private
external networks for the enterprise network.
IPv6 Capable - A node or network capable of supporting both
IPv6 and IPv4.
IPv4 only - A node or network capable of supporting only
IPv4.
IPv6 only - A node or network capable of supporting only
IPv6. This does not imply an IPv6 only stack in
this document.
3. Base Scenarios
Three base scenarios are defined to capture the essential abstraction
set for the enterprise. Each scenario has assumptions and
requirements. This is not an exhaustive set of scenarios, but a base
set of general cases.
Below we use the term network infrastructure to mean the software,
network operations and configuration, and methods used to operate a
network in an enterprise.
For the base scenarios it is assumed that any IPv6 node is IPv6
capable.
3.1. Base Scenarios Defined
Scenario 1: Wide-scale/total dual-stack deployment of IPv4 and IPv6
capable hosts and network infrastructure. Enterprise
with an existing IPv4 network wants to deploy IPv6 in
conjunction with their IPv4 network.
Assumptions: The IPv4 network infrastructure used has an equivalent
capability in IPv6.
Requirements: Do not disrupt existing IPv4 network infrastructure
assumptions with IPv6. IPv6 should be equivalent or
"better" than the network infrastructure in IPv4.
However, it is understood that IPv6 is not required to
solve current network infrastructure problems, not
solved by IPv4. It may also not be feasible to deploy
IPv6 on all parts of the network immediately.
Scenario 2: Sparse IPv6 dual-stack deployment in IPv4 network
infrastructure. Enterprise with an existing IPv4
network wants to deploy a set of particular IPv6
"applications" (application is voluntarily loosely
defined here, e.g., peer to peer). The IPv6 deployment
is limited to the minimum required to operate this set
of applications.
Assumptions: IPv6 software/hardware components for the application
are available, and platforms for the application are
IPv6 capable.
Requirements: Do not disrupt IPv4 infrastructure.
Scenario 3: IPv6-only network infrastructure with some IPv4-capable
nodes/applications needing to communicate over the IPv6
infrastructure. Enterprise deploying a new network or
restructuring an existing network, decides IPv6 is the
basis for most network communication. Some IPv4
capable nodes/applications will need to communicate
over that infrastructure.
Assumptions: Required IPv6 network infrastructure is available, or
available over some defined timeline, supporting the
enterprise plan.
Requirements: Interoperation and Coexistence with IPv4 network
infrastructure and applications are required for
communications.
3.2. Scenarios Network Infrastructure Components
This section defines the network infrastructure that exists for the
above enterprise scenarios. This is not an exhaustive list, but a
base list that can be expanded by the enterprise for specific
deployment scenarios. The network infrastructure components are
presented as functions that the enterprise must analyze as part of
defining their specific scenario. The analysis of these functions
will identify actions that are required to deploy IPv6.
Network Infrastructure Component 1
Enterprise Provider Requirements
- Is external connectivity required?
- One site vs. multiple sites and are they within different
geographies?
- Leased lines or VPNs?
- If multiple sites, how is the traffic exchanged securely?
- How many global IPv4 addresses are available to the enterprise?
- What is the IPv6 address assignment plan available from the
provider?
- What prefix delegation is required by the Enterprise?
- Will the enterprise be multihomed?
- What multihoming techniques are available from the provider?
- Will clients within the enterprise be multihomed?
- Does the provider offer any IPv6 services?
- Which site-external IPv6 routing protocols are required?
- Is there an external data center to the enterprise, such as
servers located at the Provider?
- Is IPv6 available using the same access links as IPv4, or
different ones?
Network Infrastructure Component 2
Enterprise Application Requirements
- List of applications in use?
- Which applications must be moved to support IPv6 first?
- Can the application be upgraded to IPv6?
- Will the application have to support both IPv4 and IPv6?
- Do the enterprise platforms support both IPv4 and IPv6?
- Do the applications have issues with NAT v4-v4 and NAT v4-v6?
- Do the applications need globally routable IP addresses?
- Do the applications care about dependency between IPv4 and IPv6
addresses?
- Are applications run only on the internal enterprise network?
Network Infrastructure Component 3
Enterprise IT Department Requirements
- Who "owns"/"operates" the network: in house or outsourced?
- Is working remotely (i.e., through VPNs) supported?
- Are inter-site communications required?
- Is network mobility used or required for IPv6?
- What are the requirements of the IPv6 address plan?
- Is there a detailed asset management database, including hosts,
IP/MAC addresses, etc.?
- What is the enterprise’s approach to numbering geographically
separate sites that have their own Service Providers?
- What will be the internal IPv6 address assignment procedure?
- What site internal IPv6 routing protocols are required?
- What will be the IPv6 Network Management policy/procedure?
- What will be the IPv6 QOS policy/procedure?
- What will be the IPv6 Security policy/procedure?
- What is the IPv6 training plan to educate the enterprise?
- What network operations software will be impacted by IPv6?
- DNS
- Management (SNMP & ad-hoc tools)
- Enterprise Network Servers Applications
- Mail Servers
- High Availability Software for Nodes
- Directory Services
- Are all these software functions upgradeable to IPv6?
- If not upgradeable, then what are the workarounds?
- Do any of the software functions store, display, or allow input
of IP addresses?
- Other services (e.g., NTP, etc.)
- What network hardware will be impacted by IPv6?
- Routers/switches
- Printers/Faxes
- Firewalls
- Intrusion Detection
- Load balancers
- VPN Points of Entry/Exit
- Security Servers and Services
- Network Interconnect for Platforms
- Intelligent Network Interface Cards
- Network Storage Devices
- Are all these hardware functions upgradeable to IPv6?
- If not, what are the workarounds?
- Do any of the hardware functions store, display, or allow input
of IP addresses?
- Are the nodes moving within the enterprise network?
- Are the nodes moving outside and inside the enterprise
network?
Network Infrastructure Component 4
Enterprise Network Management System
- Performance Management required?
- Network Management applications required?
- Configuration Management required?
- Policy Management and Enforcement required?
- Security Management required?
- Management of Transition Tools and Mechanisms?
- What new considerations does IPv6 create for Network Management?
Network Infrastructure Component 5
Enterprise Network Interoperation and Coexistence
- What platforms are required to be IPv6 capable?
- What network ingress and egress points to the site are required
to be IPv6 capable?
- What transition mechanisms are needed to support IPv6 network
operations?
- What policy/procedures are required to support the transition to
IPv6?
- What policy/procedures are required to support interoperation
with legacy nodes and applications?
3.3. Specific Scenario Examples
This section presents a set of base scenario examples and is not an
exhaustive list of examples. These examples were selected to provide
further clarity for base scenarios within an enterprise of a less
abstract nature. The example networks may use the scenarios depicted
in 3.1 and the infrastructure components in 3.2, but there are no
direct implications specifically within these example networks.
Section 3.1, 3.2, and 3.3 should be used in unison for enterprise
IPv6 deployment planning and analysis.
Example Network A:
A distributed network across a number of geographically
separated campuses.
- External network operation.
- External connectivity required.
- Multiple sites connected by leased lines.
- Provider independent IPv4 addresses.
- ISP does not offer IPv6 service.
- Private Leased Lines no Service Provider used.
Applications run by the enterprise:
- Internal Web/Mail.
- File servers.
- Java applications.
- Collaborative development tools.
- Enterprise Resource applications.
- Multimedia applications.
- Financial Enterprise applications.
- Data Warehousing applications.
Internal network operation:
- In house operation of the network.
- DHCP (v4) is used for all desktops; servers use static address
configuration.
- The DHCP server that updates naming records for dynamic desktops
uses dynamic DNS.
- A web based tool is used to enter name to address mappings for
statically addressed servers.
- Network management is done using SNMP.
- All routers and switches are upgradeable to IPv6.
- Existing firewalls can be upgraded to support IPv6 rules.
- Load balancers do not support IPv6, upgrade path unclear.
- Peer-2-Peer Application and Security supported.
- IPv4 Private address space is used within the enterprise.
Example Network B:
A bank running a large network supporting online
transaction processing (OLTP) across a distributed
multi-sited network, with access to a central database
on a remote network from the OLTP network.
- External connectivity not required.
- Multiple sites connected by VPN.
- Multiple sites connected by Native IP protocol.
- Private address space used with NAT.
- Connections to private exchanges.
Applications in the enterprise:
- ATM transaction application.
- ATM management application.
- Financial Software and Database.
- Part of the workforce is mobile and requires access to the
enterprise from outside networks.
Internal Network Operation:
- Existing firewalls can be upgraded to support IPv6 rules.
- Load balancers do not support IPv6, upgrade path unclear.
- Identifying and managing each node’s IP address.
Example Network C:
A Security Defense, Emergency, or other Mission Critical network
operation:
- External network required at secure specific points.
- Network is its own Internet.
- Network must be able to absorb ad-hoc creation of sub-networks.
- Entire parts of the network are completely mobile.
- All nodes on the network can be mobile (including routers).
- Network high-availability is mandatory.
- Network must be able to be managed from ad-hoc location.
- All nodes must be able to be configured from stateless mode.
Applications run by the Enterprise:
- Multimedia streaming of audio, video, and data for all nodes.
- Data computation and analysis on stored and created data.
- Transfer of data coordinate points to sensor devices.
- Data and Intelligence gathering applications from all nodes.
Internal Network Operations:
- All packets must be secured end-2-end with encryption.
- Intrusion Detection exists on all network entry points.
- Network must be able to bolt on to the Internet to share
bandwidth as required from Providers.
- VPNs can be used, but NAT can never be used.
- Nodes must be able to access IPv4 legacy applications over IPv6
network.
3.4. Applicability Statement
The specific network scenarios selected are chosen to depict a base
set of examples, and to support further analysis of enterprise
networks. This is not a complete set of network scenarios. Though
Example Network C is a verifiable use case, currently the scenario
defines an early adopter of enterprise networks transitioning to IPv6
as a predominant protocol strategy (i.e., IPv6 Routing, Applications,
Security, and Operations), viewing IPv4 as legacy operations
immediately in the transition strategy, and at this time may not be
representative of many initial enterprise IPv6 deployments. Each
enterprise planning team will need to make that determination as IPv6
deployment evolves.
4. Network Infrastructure Component Requirements
The enterprise will need to determine which network infrastructure
components require enhancements or need to be added for deployment of
IPv6. This infrastructure will need to be analyzed and understood as
a critical resource to manage. The list in this section is not
exhaustive, but contains the essential network infrastructure
components for the enterprise to consider before beginning to define
more fine-tuned requirements such as QOS, PKI, or Bandwidth
requirements for IPv6. The components are only identified here and
their details will be discussed in the analysis document for
enterprise scenarios. References currently available for components
are provided.
4.1. DNS
DNS will now have to support both IPv4 and IPv6 DNS records and the
enterprise will need to determine how the DNS is to be managed and
accessed, and secured. The range of DNS operational issues is beyond
the scope of this document. However, DNS resolution and transport
solutions for both IP protocols are influenced by the chosen IPv6
deployment scenario. Users need to consider all current DNS IPv4
operations and determine if those operations are supported for IPv6
[DNSV6].
4.2. Routing
Interior and Exterior routing will be required to support both IPv4
and IPv6 routing protocols, and the coexistence of IPv4 and IPv6 over
the enterprise network. The enterprise will need to define the IPv6
routing topology, any ingress and egress points to provider networks,
and transition mechanisms that they wish to use for IPv6 adoption.
The enterprise will also need to determine what IPv6 transition
mechanisms are supported by their upstream providers.
4.3. Configuration of Hosts
IPv6 introduces the concept of stateless autoconfiguration in
addition to stateful autoconfiguration, for the configuration of
hosts within the enterprise. The enterprise will have to determine
the best method of host configuration for its network, if it will use
stateless or stateful autoconfiguration, and how autoconfiguration
will operate for DNS updates. It will also need to determine how
prefix delegation will be done from their upstream provider and how
those prefixes will be cascaded down to the enterprise IPv6 network.
The policy for DNS or choice of autoconfiguration is out of scope for
this document [CONF, DHCPF, DHCPL].
4.4. Security
Current existing mechanisms used for IPv4 to provide security need to
be supported for IPv6 within the enterprise. IPv6 should create no
new security concerns for IPv4. The entire security infrastructure
currently used in the enterprise needs to be analyzed against IPv6
deployment effect to determine what is supported in IPv6. Users
should review other current security IPv6 network infrastructure work