Coexistence and Migration

1
Lesson 11
Coexistence and Migration
2
Lesson Objectives

• Coexistence and migration overview
• Coexistence mechanisms
• Tunneling configurations
• 6over4
• 6to4
• ISATAP
• PortProxy
• Migrating to IPv6

3
Coexistence and Migration Overview

• The transition from IPv4 to IPv6 will take years
• Some hosts will use IPv4 indefinitely
• Migration is the long term goal, coexistence in
  the interim
• Transition criteria
• Existing IPv4 hosts can be upgraded at any time
  independent of the upgrade of other hosts or
  routers
• New hosts using only IPv6 can be added at any
  time without dependencies on other hosts or
  routing infrastructure
• Existing IPv4 hosts with IPv6 installed can
  continue to use their IPv4 address and do not
  need additional addresses
• Little preparation is needed to upgrade existing
  IPv4 nodes to IPv6 or to deploy new IPv6 nodes

4
Node Types

• IPv4-only node
• IPv6-only node
• IPv6/IPv4 node
• IPv4 node
• IPv6 node

5
Compatibility Addresses

• IPv4-compatible addresses
• w.x.y.z
• IPv4-mapped addresses
• FFFFw.x.y.z
• 6over4 addresses
• Interface ID of WWXXYYZZ
• 6to4 addresses
• Prefix of 2002WWXXYYZZ/48
• ISATAP addresses
• Interface ID of 05EFEw.x.y.z

6
Coexistence Mechanisms

• Dual IP layer
• IPv6 over IPv4 tunneling
• DNS infrastructure

7
Dual IP Layer Architecture
Application Layer
Transport Layer (TCP/UDP)
IPv6
IPv4
Network Interface Layer
8
Dual Stack Architecture
Application Layer
TCP/UDP
TCP/UDP
IPv6
IPv4
Network Interface Layer
9
IPv6 over IPv4 Tunneling
IPv6 Packet
IPv6 Header
Extension Headers
Upper Layer Protocol Data Unit
IPv6 Header
Extension Headers
Upper Layer Protocol Data Unit
IPv4 Header
IPv4 Packet
10
DNS Infrastructure

• Address records
• A records for IPv4 nodes
• AAAA records for IPv6 nodes
• Pointer records
• PTR records in IN-ADDR.ARPA domain for IPv4 nodes
• PTR records in IP6.INT domain for IPv6 nodes
• Address selection rules
• Choosing the best set of addresses with which
  to communicate

11
Tunneling Configurations

• Router-to-Router
• Host-to-Router and Router-to-Host
• Host-to-Host

12
Router-to-Router Tunneling
IPv4 Infrastructure
IPv4 or IPv6 Infrastructure
IPv4 or IPv6 Infrastructure
IPv6 Node
IPv6 Node
IPv6/IPv4 Router
IPv6/IPv4 Router
13
Host-to-Router and Router-to-Host Tunneling
IPv4 Infrastructure
IPv4 or IPv6 Infrastructure
Node A
Node B
IPv6/IPv4
IPv6
IPv6/IPv4 Router
14
Host-to-Host Tunneling
IPv4 Infrastructure
IPv6/IPv4 Node
IPv6/IPv4 Node
15
Types of Tunnels

• Configured
• Manual configuration of tunnel endpoints
• Automatic
• Tunnel endpoints determined from use of logical
  tunnel interfaces, routes, and source and
  destination IPv6 addresses
• IPv6 Automatic Tunneling
• Uses IPv4-compatible addresses

16
6over4 Overview

• Host-to-host, host-to-router, and router-to-host
  automatic tunneling technology
• 6over4 address
• 64-bit prefixWWXXYYZZ
• Link-local 6over4 address FE80WWXXYYZZ
• 6over4 treats an IPv4 multicast-enabled
  infrastructure as a single multicast-capable link
• Used for unicast and multicast IPv6 traffic over
  an IPv4 infrastructure

17
6over4
Host B
IPv4 Multicast-Enabled Infrastructure
Host A
IPv6 Infrastructure
6over4 Host
6over4 Host
IPv6/IPv4 Router
Logical Equivalent
Host B
IPv6 Infrastructure
IPv6/IPv4 Router
Host A
18
Source and Target Link-Layer Address Options for
6over4
Type Length Address
1
Zero
IPv4 Address
19
6to4 Overview

• Address assignment and router-to-router automatic
  tunneling technology
• 6to4 address
• 2002WWXXYYZZSLA IDInterface ID
• 6to4 treats the IPv4 Internet as a single link
• Used for unicast traffic over the IPv4 Internet

20
6to4 Components
6to4 Relay Router IPv6/IPv4
IPv6 Internet
IPv6 Host D IPv6-only
6to4 Host C IPv6/IPv4
Internet
Site 2
6to4 Router IPv6/IPv4
6to4 Router IPv6/IPv4
6to4 Host A IPv6/IPv4
6to4 Host B IPv6/IPv4
Site 1
21
6to4 Support in Windows

• With public IPv4 address, automatic configuration
  as a 6to4 host/router
• Able to communicate with other 6to4 sites
• Able to communicate with IPv6 Internet
• With ICS, automatic configuration as a 6to4
  router
• Enables forwarding
• Sends routing advertisements with 6to4 prefixes
• SLA ID Interface index of intranet interface

22
6to4 for Windows
6to4 Relay Router IPv6/IPv4
IPv6 Internet
IPv6 Host D IPv6-only
6to4 Host C IPv6/IPv4
Internet
Site 2
Site 3
6to4 Router IPv6/IPv4
6to4 Host/Router E IPv6/IPv4
6to4 Router IPv6/IPv4
6to4 Host A IPv6/IPv4
6to4 Host B IPv6/IPv4
Site 1
23
ISATAP Overview

• Address assignment and host-to-host,
  host-to-router, and router-to-host automatic
  tunneling technology
• ISATAP addresses
• 64-bit prefix05EFEw.x.y.z
• ISATAP treats an IPv4 infrastructure as a single
  link
• Used for unicast traffic across an IPv4 intranet

24
Link-Local ISATAP Configuration
ISATAP Host A FE805EFE10.40.1.29
IPv4 Infrastructure
ISATAP Host B FE805EFE192.168.41.30
25
ISATAP Router Configuration
Example prefix 3FFE2900D0057/64
IPv6 network
IPv4 Infrastructure
ISATAP Router
ISATAP Host B 3FFE2900D00575EFE192.168.41.30

• ISATAP router
• Responds to tunneled router solicitations from
  ISATAP hosts
• Forward traffic between ISATAP hosts and other
  IPv6 subnets

26
ISATAP and 6to4 Example
27
PortProxy Service

• TCP proxy for
• IPv4 to IPv4
• IPv4 to IPv6
• IPv4-only host can communicate with IPv6-only
  server or application
• IPv6 to IPv6
• IPv6 to IPv4
• IPv4-only host can communicate with IPv6-only
  server or application
• Use to IPv6-enable IPv4-only applications
  running on a Windows .NET Server computer

28
PortProxy Coexistence Scenarios

• An IPv4-only node can access an IPv6-only node
• An IPv6-only node can access an IPv4-only node
• An IPv6 node can access an IPv4-only service
  running on an IPv6/IPv4 node

29
Migrating to IPv6

• 1. Upgrade your applications to be independent of
  IPv4 or IPv6
• 2. Update the DNS infrastructure to support IPv6
  addresses and PTR records
• 3. Upgrade hosts to IPv4/IPv6 nodes
• 4. Upgrade routing infrastructure for native IPv6
  routing
• 5. Convert IPv4/IPv6 nodes to IPv6-only nodes

30
Review

• Coexistence and migration overview
• Coexistence mechanisms
• Tunneling configurations
• 6over4
• 6to4
• ISATAP
• PortProxy
• Migrating to IPv6