資 管 Lee Lesson 11 Coexistence and Migration

資 管 Lee Lesson Objectives Coexistence and migration overview Coexistence mechanisms ◦ Dual Stack ◦ Tunneling ◦ Translation Tunneling configurations ◦ 6over4 ◦ 6to4 ◦ ISATAP ◦ PortProxy Migrating to IPv6

資 管 Lee 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:( in RFC 1752) ◦ 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

資 管 Lee Node Types IPv4-only node ◦ Implements only IPv4. This node does not support IPv6 IPv6-only node IPv6/IPv4 node IPv4 node ◦ An IPv4 node implements IPv4. It can be an IPv4- only node or an IPv6/IPv4 node. IPv6 node

資 管 Lee Coexistence Mechanisms Three categories ◦ Dual stack (IP layer and Connection) ◦ Tunneling (IPv6 over IPv4 connection) ◦ NAT (Network Address Translation IPv4  IPv6) DNS infrastructure for IPv6

資 管 Lee Dual stack (IP layer and Connection) IPv6/IPv4 node (Dual IP layer) Internet(IPv4) Internet(IPv6) Dual Connection

資 管 Lee Application Layer Transport Layer (TCP/UDP) IPv6 Network Interface Layer IPv4 Dual IP Layer Architecture Conceptual Architecture

資 管 Lee Application Layer TCP/UDP IPv6 Network Interface Layer TCP/UDP IPv4 Dual Stack Architecture Actual Implementation in XP and.net 2003

資 管 Lee IPv6 Header Extension Headers Upper Layer Protocol Data Unit IPv6 Packet IPv6 Header Extension Headers Upper Layer Protocol Data Unit IPv4 Header IPv4 Packet Tunneling (IPv6 over IPv4,Generic Concept) 1. Protocol field in IPv4 Header is set to 41 2.Src/Des fields of IPv4 Header are set to tunnel endpoints IPv4 Infrastructure IPv6 node IPv6 over IPv4 Tunnel Node A Node B IPv6 node

資 管 Lee Compatibility Addresses IPv4-compatible addresses ◦ ::w.x.y.z (0:0:0:0:0:0:w.x.y.z) ◦ Used by IPv6/IPv4 node. When IPv4-compatiable address is used as an IPv6 destination, the IPv6 traffic is automatically encapsulated with an IPv4 header and sent to IPv4 Infrastructure. IPv4-mapped addresses ◦ ::FFFF:w.x.y.z (0:0:0:0:0: FFFF:w.x.y.z) ◦ Used to represent an IPv4-only node to an IPv6 node. It is used only for internal representation. Never used as a SRC/DST addresses of an IPv6 packet. 6over4 addresses ◦ Interface ID of ::WWXX:YYZZ (prefix + ::WWXX:YYZZ) ◦ RFC 2529, 6over4 addresses are assigned to IPv6 nodes that are connected to an IPv4 multicast-enabled infrastructure. 6to4 addresses ◦ Prefix of 2002:WWXX:YYZZ::/48 ◦ RFC 3056, 6to4 address prefixes are used to create global address prefixes for sites and global addresses for IPv6 within sites.

資 管 Lee ISATAP addresses ◦ valid 64-bit unicast address prefix and the interface I ID of ::0:5EFE:w.x.y.z ◦ Example of link-local ISATAP address is FE80::5EFE: ◦ When Intra-Site Automatic Tunnel Addressing Protocol (ISATAP) is used, addresses using ISATAP-derived interface identifiers are assigned to IPv6/IPv4 nodes.

資 管 Lee Tunneling Configurations Router-to-Router ◦ Two IP infrastructures are connected by two IPv6/IPv4 routers over an IPv4 infrastructure. ◦ Examples:  An IPv6 test lab. Tunnels across IPv4 to reach the IPv6 Internet. IPv4 or IPv6 Infrastructure IPv4 Infrastructure IPv6 over IPv4 Tunnel IPv6/IPv4 Router IPv6 Node IPv6 Node IPv4 or IPv6 Infrastructure

資 管 Lee Host-to-Router and Router-to-Host ◦ An IPv6/IPv4 node that resides within an IPv4 infrastructure creates an IPv6 over IPv4 tunnel to reach an IPv6/IPv4 router. ◦ Examples:  An ISATAP host that tunnels across an IPv4 network to an ISATAP router to reach the another IPv4 Internet, or an IPv6 network.  An ISATAP router tunnels across an IPv4 network to reach an ISATAP host (route-to-host) IPv4 Infrastructure IPv6/IPv4IPv6 IPv6/IPv4 Router IPv6 over IPv4 Tunnel Node A Node B IPv4 or IPv6 Infrastructure

資 管 Lee Host-to-Host ◦ An IPv6/IPv4 node that resides within an IPv4 infrastructure creates an IPv6 over IPv4 tunnel to reach another IPv6/IPv4 node that resides within the same IPv4 infrastructure. ◦ Examples:  IPv6/IPv4 hosts that use ISATAP addresses to tunnel across an organization’s IPv4 infrastructure.  IPv6/IPv4 hosts that use IPv4-compatible addresses to tunnel across an organization’s IPv4 infrastructure. IPv4 Infrastructure IPv6/IPv4 Node IPv6/IPv4 Node IPv6 over IPv4 Tunnel

資 管 Lee Types of Tunnels Configured ◦ Manual configuration of IPv4 tunnel endpoints ◦ The two endpoints are not encoded in the IPv6 Source and destination addresses, nor in the next-hop address of the matching route. ◦ Typical router-to-router and host-to-router tunneling configurations are configured manually. Automatic ◦ tunnel endpoints are decided by the use of logical tunnel interfaces, routes, and source and destination of IPv6 address. ◦ Usually, a host-to-host tunnel between two IPv6/IPv4 hosts using IPv4- compatible addresses. ◦ For example, Host A (IPv4: its IPv4-compatible addresses is: :: ) communicate with Host B (IPv4: its IPv4-compatible addresses is: :: ) Ping :: (test connectivity) (XP are disabled by default, link-local ISATAP is used instead)

資 管 Lee Note: ◦ IPv6 Automatic Tunneling [in this book]  Uses IPv4-compatible addresses ◦ Automatic Tunneling  Refers to tunneling without manual configuration, independent of the type of addressing being used.

資 管 Lee 6over4 Overview IPv4 multicast tunneling is a host-to-host, host-to-router, and router-to-host automatic tunneling technology that provide unicast and multicast of IPv6 across an IPv4 intranet. 6over4 address: ◦ [64-bit prefix]::WWXX:YYZZ ◦ Link-local 6over4 address FE80::WWXX:YYZZ 6over4 treats an IPv4 multicast-enabled infrastructure as a single multicast-capable link FF02::1 is mapped to

資 管 Lee 資 管 IPv4 Multicast-Enabled Infrastructure IPv6 Infrastructure Host B 6over4 Host IPv6/IPv4 Router Logical Equivalent IPv6 Infrastructure IPv6/IPv4 Router 6over4 Host Host A Host B IPv6 over IPv4 Tunnel 6over4 Host A: FE80::9D3C:5B7B Host A: FE80::836B:D231 Router: FE80::C0A8:1501 Router Advertisement: Source address: FE80::C0A8:1501 Prefix : FEC0:0:0:21A8/64

資 管 Lee Type Length Address = 1 ZeroIPv4 Address Source and Target Link-Layer Address Options for 6over4 Router Advertisement: Source address: FE80::C0A8:1501 Prefix : FEC0:0:0:21A8/64 After Router Advertisement: Hosts construct routing table: fec0:0:0:21a8::/64 5 6over4 tunneling Interface ::/0 5 fe80::c0a8:1501

資 管 Lee 6to4 Overview Address assignment and router-to-router automatic tunneling technology 6to4 address: ◦ 2002:WWXX:YYZZ:[SLA ID]:[Interface ID] 6to4 treats the IPv4 Internet as a single link Used for unicast traffic over the IPv4 Internet

資 管 Lee 資 管 6to4 Relay Router IPv6/IPv4 6to4 Router IPv6/IPv4 IPv6 Internet 6to4 Host A IPv6/IPv4 6to4 Host C IPv6/IPv4 6to4 Router IPv6/IPv4 Internet 6to4 Host B IPv6/IPv4 Site 2 IPv6 Host D IPv6-only Site 1 6to4 Components

資 管 Lee 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

資 管 Lee 6to4 Relay Router IPv6/IPv4 6to4 Router IPv6/IPv4 IPv6 Internet 6to4 Host A IPv6/IPv4 6to4 Host C IPv6/IPv4 6to4 Router IPv6/IPv4 6to4 Host B IPv6/IPv4 Site 2 IPv6 Host D IPv6-only 6to4 Host/Router E IPv6/IPv4 Site 3 Site 1 6to4 for Windows Internet

資 管 Lee ISATAP Overview Address assignment and host-to-host, host- to-router, and router-to-host automatic tunneling technology ISATAP addresses: ◦ [64-bit prefix]:0:5EFE:w.x.y.z] ◦ [64-bit prefix] includes link-local prefix, site-local prefixes, and global prefixes (include 6to4 prefix) ISATAP treats an IPv4 infrastructure as a single link Used for unicast traffic across an IPv4 intranet

資 管 Lee ISATAP Host B FE80::5EFE: ISATAP Host A FE80::5EFE: Link-Local ISATAP Configuration IPv4 Infrastructure IPv4 Host A IPv4 Host B FieldValue IPv6 Source AddressFE80::5EFE: IPv6 Dest. AddressFE80::5EFE: IPv4 Source Address IPv4 Dest. Address Host A sends IPv6 traffic to Host B

資 管 Lee IPv4 Infrastructure ISATAP Host B 3FFE:2900:D005:7:5EFE: ISATAP Router Configuration ISATAP router ◦ Responds to tunneled router solicitations from ISATAP hosts ◦ Forward traffic between ISATAP hosts and other IPv6 subnets ISATAP Router IPv6 network Example prefix: 3FFE:2900:D005:7::/64 IPv6 over IPv4 Tunnel

資 管 Lee Internet ISATAP Host B 2002:836B:1:2:0:5EFE: IPv4 Infrastructure ISATAP Host A 2002:9D36:1:2:0:5EFE: Part 3 Part 2 Part 1 6to4 Router A IPv6/IPv to4 Router B IPv6/IPv IPv4 Infrastructure Site A Site B ISATAP and 6to4 Example Two ISATAP hosts using 6to4 prefixes that are communicating Across the Internet even though Each site is using the /16

資 管 Lee Internet(IPv4) NAT (Network Address Translation IPv4  IPv6) Internet(IPv6) NAT Router

資 管 Lee 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

資 管 Lee 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

資 管 Lee 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 ◦ After the querying, node obtains the set of addresses corresponding to the name. ◦ The querying node is configured with at least one IPv4 address and multiple IPv6 addresses (public vs. private for IPv4 and link-local vs. site-local vs. global vs. coexistence IPv6 addresses) ◦ Choosing the “best” set of addresses with which to communicate

資 管 Lee AAAA record fields (RFC 3596 vs. A6 in RFC 2874) NAMEDomain name TYPEAAAA (28) CLASSInternet (1) TTLTime to live in seconds RDLENGTHLength of RDATA field RDATAString form of the IPV6 address as described in RFC 3513RFC 3513

資 管 Lee 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