資管 lee lesson 11 coexistence and migration. 資管 lee lesson objectives coexistence and...

資管 Lee <Lesson 11-1>

Lesson 11

Coexistence and Migration


Lesson ObjectivesCoexistence and migration overviewCoexistence mechanisms

◦Dual Stack◦Tunneling◦Translation

Tunneling configurations◦6over4◦6to4◦ISATAP◦PortProxy

Migrating to IPv6


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


Node Types

IPv4-only node◦Implements only IPv4. This node does not

support IPv6IPv6-only nodeIPv6/IPv4 nodeIPv4 node

◦An IPv4 node implements IPv4. It can be an IPv4-only node or an IPv6/IPv4 node.

IPv6 node


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


Dual stack (IP layer and Connection)

IPv6/IPv4 node(Dual IP layer)

Internet(IPv4)

Internet(IPv6)

Dual Connection


ApplicationLayer

Transport Layer (TCP/UDP)

IPv6

Network Interface Layer

IPv4

Dual IP Layer ArchitectureConceptual Architecture


ApplicationLayer

TCP/UDP

IPv6

Network Interface Layer

TCP/UDP

IPv4

Dual Stack ArchitectureActual Implementation in XP and .net 2003


IPv6 HeaderExtensionHeaders

Upper Layer Protocol Data Unit

IPv6 Packet

IPv6 HeaderExtensionHeaders

Upper Layer Protocol Data Unit

IPv4 Header

IPv4 Packet

Tunneling (IPv6 over IPv4,Generic Concept)1. Protocol field in IPv4 Header is

set to 412.Src/Des fields of IPv4 Header are set to tunnel endpoints

IPv4 Infrastructure

IPv6 node

IPv6 over IPv4 Tunnel

Node ANode B

IPv6 node


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.


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:131.107.4.92◦When Intra-Site Automatic Tunnel

Addressing Protocol (ISATAP) is used, addresses using ISATAP-derived interface identifiers are assigned to IPv6/IPv4 nodes.


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/IPv4 Router IPv6/IPv4 Router

IPv6Node

IPv6Node

IPv4 or IPv6 Infrastructure


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/IPv4 IPv6

IPv6/IPv4 Router


Node A Node BIPv4 or IPv6 Infrastructure


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/IPv4Node

IPv6/IPv4Node



Types of TunnelsConfigured

◦ 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: 157.60.91.123 its IPv4-compatible addresses

is: :: 157.60.91.123) communicate with Host B (IPv4: 131.107.210.49 its IPv4-compatible addresses is: :: 131.107.210.49)

Ping :: 131.107.210.49 (test connectivity)(XP are disabled by default, link-local ISATAP is used

instead)


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.


6over4 OverviewIPv4 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:YYZZ6over4 treats an IPv4 multicast-

enabled infrastructure as a single multicast-capable link

FF02::1 is mapped to 239.192.0.1


資管

IPv4 Multicast-Enabled Infrastructure

IPv6 Infrastructure

Host B

6over4Host IPv6/IPv4

Router

LogicalEquivalent

IPv6 Infrastructure

IPv6/IPv4Router

6over4Host

Host A

Host A

Host B


6over4

Host A: 157.60.91.123FE80::9D3C:5B7B

Host A: 131.107.210.49FE80::836B:D231

Router: 192.168.69.1FE80::C0A8:1501

Router Advertisement:Source address: FE80::C0A8:1501Prefix : FEC0:0:0:21A8/64


TypeLength

Address= 1

Zero IPv4 Address

Source and Target Link-Layer Address Options for 6over4

Router Advertisement:Source address: FE80::C0A8:1501Prefix : 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


6to4 OverviewAddress 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

6to4 Relay RouterIPv6/IPv4

6to4 RouterIPv6/IPv4

IPv6Internet

6to4 Host AIPv6/IPv4

6to4 Host CIPv6/IPv4


Internet

6to4 Host BIPv6/IPv4

Site 2

IPv6 Host DIPv6-only

Site 1

6to4 Components


6to4 Support in WindowsWith 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


6to4 Relay RouterIPv6/IPv4


IPv6Internet

6to4 Host AIPv6/IPv4

6to4 Host CIPv6/IPv4


6to4 Host BIPv6/IPv4

Site 2

IPv6 Host DIPv6-only

6to4 Host/Router EIPv6/IPv4

Site 3

Site 1

6to4 for Windows

Internet


ISATAP OverviewAddress 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


ISATAP Host BFE80::5EFE:192.168.41.30

ISATAP Host AFE80::5EFE:10.40.1.29

Link-Local ISATAP Configuration

IPv4 Infrastructure

IPv4 Host A10.40.1.29

IPv4 Host B192.168.41.30

Field Value

IPv6 Source Address FE80::5EFE:10.40.1.29

IPv6 Dest. Address FE80::5EFE:192.168.41.30

IPv4 Source Address 10.40.1.29

IPv4 Dest. Address 192.168.41.30

Host A sends IPv6 traffic to Host B


IPv4Infrastructure

ISATAP Host B3FFE:2900:D005:7:5EFE:192.168.41.30

ISATAP Router Configuration

ISATAP router◦Responds to tunneled router solicitations from

ISATAP hosts◦Forward traffic between ISATAP hosts and other

IPv6 subnets

ISATAPRouter

IPv6network

Example prefix: 3FFE:2900:D005:7::/64

IPv6 over IPv4

Tunnel


131.107.0.1

Internet

ISATAP Host B2002:836B:1:2:0:5EFE:192.168.141.30

157.54.0.1

IPv4 Infrastructure

ISATAP Host A2002:9D36:1:2:0:5EFE:192.168.12.9

Part 3

Part 2

Part 1

6to4 Router AIPv6/IPv4

192.168.204.1

6to4 Router BIPv6/IPv4

192.168.39.1

IPv4 Infrastructure

192.168.12.9

192.168.141.30

Site A

Site B

ISATAP and 6to4 Example

Two ISATAP hosts using 6to4 prefixes that are communicatingAcross the Internet even thoughEach site is using the 192.168.0.0/16


Internet(IPv4)

NAT (Network Address Translation IPv4 IPv6)

Internet(IPv6)

NATRouter


PortProxy ServiceTCP 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


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


DNS InfrastructureAddress 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


AAAA record fields (RFC 3596 vs. A6 in RFC 2874)

NAME Domain name

TYPE AAAA (28)

CLASS Internet (1)

TTL Time to live in seconds

RDLENGTH Length of RDATA field

RDATA String form of the IPV6 address as described in RFC 3513

http://en.wikipedia.org/wiki/Time_to_live

http://tools.ietf.org/html/rfc3513


Migrating to IPv61. Upgrade your applications to be

independent of IPv4 or IPv62. Update the DNS infrastructure to

support IPv6 addresses and PTR records

3. Upgrade hosts to IPv4/IPv6 nodes4. Upgrade routing infrastructure for

native IPv6 routing5. Convert IPv4/IPv6 nodes to IPv6-only

nodes

資管 lee lesson 11 coexistence and migration. 資管 lee lesson objectives coexistence and...

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資 管 lee lesson 11 coexistence and migration. 資 管 lee lesson objectives coexistence and...

資管 lee lesson 11 coexistence and migration. 資管 lee lesson objectives coexistence and...