ZyXEL Confidential IPv6: Addressing Milo Liu SW2 ZyXEL Communications Corp. 3/6/2006

ZyXEL Confidential Outline  Review IPv4 addressing.  Basic IPv6 address concepts.  IPv6 address space.  Subnetting IPv6 space.

ZyXEL Confidential IPv4 Address  32bit address space.  Subnet defined by a mask.  Unicast host address.  Multicast address.  Broadcast address.  Special address.

ZyXEL Confidential IPv4 Address  32 bits address space  Subnet mask (Network section and host section) A class (0xxxxxxx) + 24 bit B class (10xxxxxxxxxxxxxx) + 16bits C class (110xxxxxxxxxxxxxxxxxxxxx) + 8bits

ZyXEL Confidential IPv4 Address  Multicast address. 1110xxxx + 24bits (223 ~ 240).xxxxx  Broadcast address  Loop-back address (localhost)

ZyXEL Confidential IPv4 Addresses and IPv6 Equivalents IPv4 AddressIPv6 Address Internet address classesN/A Multicast addresses ( /4)IPv6 multicast addresses (FF00::/8) Broadcast addressesN/A Unspecified address is Unspecified address is :: Loopback address is Loopback address is ::1 Public IP addressesAggregatable global unicast addresses Private IP addressesSite-local addresses (FEC0::/48) APIPA addressesLink-local addresses (FE80::/64) Dotted decimal notationColon hexadecimal format Subnet mask or prefix lengthPrefix length notation only

ZyXEL Confidential  IPV6 Address syntax. 128bits space. (split by 16bits) IPv6 Address concept DA:00D3:0000:2F3B:02AA:00FF:FE28:9C5A 21DA:D3:0:2F3B:2AA:FF:FE28:9C5A Prefix (n)Interface ID (128 - n) 128 bits

ZyXEL Confidential IPv6 Address concept  IPv6 address syntax: Compressing Zeros FE80:0:0:0:2AA:FF:FE9A:4CA2 becomes FE80::2AA:FF:FE9A:4CA2 FF02:0:0:0:0:0:0:2 FF02::2

ZyXEL Confidential IPv6 Address concept  Prefix is part of address where the bits have fixed values or are the bits of a route or subnet identifier.  IPv6 subnets or routes always uses address/prefix-length notation. ( Classless Inter-Domain Routing (CIDR) ) 21DA:D3::/48 for a route 21DA:D3:0:2F3B::/64 for a subnet

ZyXEL Confidential Classless Inter-Domain Routing (CIDR)

ZyXEL Confidential IPv6 Addresses Application Router 1 Subnet 2 Subnet 1 Router 2 Host A Host B Site: FEC0::1: 20D:60FF:FECB:6255 Link: FE80::20D:60FF:FECB:6255 Multicast: FF01::1 FF02::1 FF02::1:FFCB:6255 internet Global: 3000:4D:C00:: 20D:60FF:FECB:6255

ZyXEL Confidential IPv6 Address concept  Subnet Mask: not required and as prefix of IPv6 address  Type of address Unicast –Address of a single interface –One-to-one delivery to single interface Multicast –Address of a set of interfaces –One-to-many delivery to all interfaces in the set Anycast –Address of a set of interfaces –One-to-one-of-many delivery to a single interface in the set that is closest No broadcast addresses

ZyXEL Confidential IPv6 Address concept  Unicast address Aggregatable global unicast addresses Link-local addresses Site-local addresses Special addresses Compatibility addresses NSAP addresses

ZyXEL Confidential IPv6 Address concept  IPv6 Address space 64bits (subnet section) + 64bits (interface section) Prefix Interface ID 64 bits

ZyXEL Confidential Unicast address  Aggregatable global unicast addresses Top-Level Aggregation ID (TLA ID) Next-Level Aggregation ID (NLA ID) Site-Level Aggregation ID (SLA ID) Interface ID TLA IDInterface ID 13 bits64 bits SLA ID 24 bits 001NLA ID 16 bits Res 8 bits

ZyXEL Confidential Unicast address  Topologies Within Global Addresses Public Topology Site Topology Interface ID TLA IDInterface ID 64 bits SLA ID001NLA ID 16 bits Res 48 bits Public Topology Site TopologyInterface Identifier

ZyXEL Confidential Unicast address  Link-local addresses Used between on-link neighbors and for Neighbor Discovery Format Prefix –FE80::/64 prefix Used for local link only –Single subnet, no router –Address autoconfiguration –Neighbor Discovery

ZyXEL Confidential Unicast address  Link-local addresses Interface ID 10 bits64 bits bits

ZyXEL Confidential Unicast address  Site-local addresses Used between nodes in the same site Format Prefix –FEC0::/48 prefix for site Used for local site only –Replacement for IPv4 private addresses –Intranets not connected to the Internet –Routers do not forward site-local traffic outside the site

ZyXEL Confidential Unicast address  Site-local addresses Interface ID 10 bits64 bits bits Subnet ID 16 bits

ZyXEL Confidential Unicast address  Special addresses Unspecified address –0:0:0:0:0:0:0:0 or :: Loopback address –0:0:0:0:0:0:0:1 or ::1

ZyXEL Confidential Unicast address  Compatibility Addresses IPv4-compatible address –0:0:0:0:0:0:w.x.y.z or ::w.x.y.z IPv4-mapped address –0:0:0:0:0:FFFF:w.x.y.z or ::FFFF:w.x.y.z 6over4 address –[64-bit prefix]:0:0:WWXX:YYZZ 6to4 address –2002:WWXX:YYZZ:[SLA ID]:[Interface ID] ISATAP address –Interface ID of ::0:5EFE:w.x.y.z

ZyXEL Confidential Multicast IPv6 Address  Defined multicast addresses All-Nodes addresses –FF01::1 (Node Local), FF02::1 (Link Local) All-Routers addresses –FF01::2 (Node Local), FF02::2 (Link Local), FF05::2 (Site Local) 1111 Group ID 8 bits112 bits Flags 4 bits Scope 4 bits

ZyXEL Confidential Scope: 4bits

ZyXEL Confidential Multicast IPv6 Address  Recommended Multicast IPv6 Addresses Single IPv6 multicast address maps to a single Ethernet multicast MAC address 1111 Group ID 8 bits32 bits Flags 4 bits Scope 4 bits80 bits 000 … 000

ZyXEL Confidential Multicast IPv6 Address  Solicited-Node Address Acts as a pseudo-unicast address for very efficient address resolution For FE80::2AA:FF:FE28:9C5A, the corresponding solicited-node address is FF02::1:FF28:9C5A

ZyXEL Confidential Multicast IPv6 Address  Solicited-Node Address Interface ID 64 bits Unicast prefix 64 bits FF02: 24 bits :1:FF0:0:0:0

ZyXEL Confidential Anycast IPv6 Address  An anycast address is an address that is assigned to a set of interfaces that typically belong to different nodes.  A packet sent to an anycast address is delivered to the closest interface.  Anycast addresses can be used only by a router, not a host, and anycast addresses must not be used as the source address of an IPv6 packet.  Subnet router anycast address

ZyXEL Confidential IPv6 Addresses Application  IPv6 Addresses for a Host Unicast addresses: –A link-local address for each interface –Unicast addresses for each interface (site-local or global addresses) –A loopback address (::1) Listen Multicast addresses: –The node-local scope all-nodes multicast address (FF01::1) –The link-local scope all-nodes multicast address (FF02::1) –The solicited-node address for each unicast address –The multicast addresses of joined groups

ZyXEL Confidential IPv6 Addresses Application  IPv6 Addresses for a Router Unicast addresses: –A link-local address for each interface –Unicast addresses for each interface –Loopback address (::1) Anycast addresses –Subnet-router anycast address –Additional anycast addresses (optional) Listen Multicast addresses: –The node-local scope all-nodes multicast address (FF01::1) –The node-local scope all-routers multicast address (FF01::2) –The link-local scope all-nodes multicast address (FF02::1) –The link-local scope all-routers multicast address (FF02::2) –The site-local scope all-routers multicast address (FF05::2) –The solicited-node address for each unicast address –The multicast addresses of joined groups

ZyXEL Confidential IPv6 Addresses Application Router 1 Subnet 2 Subnet 1 Router 2 Host A Host B Site: FEC0::1: 20D:60FF:FECB:6255 Link: FE80::20D:60FF:FECB:6255 Multicast: FF01::1 FF02::1 FF02::1:FFCB:6255 internet Global: 3000:4D:C00:: 20D:60FF:FECB:6255

ZyXEL Confidential IPv6 Interface Identifiers  Interface identifier based on: Extended Unique Identifier (EUI)-64 address –Either assigned to a network adapter card or derived from IEEE 802 addresses Temporarily assigned, randomly generated value that changes over time A value assigned by a stateful address configuration protocol A value assigned during a Point-to-Point Protocol connection establishment A manually configured value

ZyXEL Confidential IEEE EUI-64 Addresses  Extended Unique Identifier  Company ID  Extension ID ccccccug cccccccc cccccccc 24 bits40 bits xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx IEEE-administered company IDManufacturer-selected extension ID

ZyXEL Confidential IPv6 Interface Identifiers  Extended Unique Identifier (EUI)-64 address Extended Unique Identifier Company ID Extension ID ccccccug cccccccc cccccccc 24 bits40 bits xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx IEEE-administered company IDManufacturer-selected extension ID

ZyXEL Confidential Conversion of an IEEE 802 Address to an EUI-64 Address  Host A has the MAC address of 00-0D-60-CB Convert to EUI-64 format –00-0D-60-FF-FE-CB Complement the U/L bit –The first byte in binary form is When the seventh bit is complemented, it becomes (0x02). –Result is 02-0D-60-FF-FE-CB Convert to colon hexadecimal notation –20D:60FF:FECB:6255  Link-local address for node with the MAC address of 00-0D-60-CB is FE80:: 20D:60FF:FECB:6255.

ZyXEL Confidential xFF0xFE EUI-64 Address bits IEEE-administered company IDManufacturer-selected extension ID IEEE 802 Address bits IPv6 Interface Identifier

ZyXEL Confidential Temporary Address Interface Identifiers  Random IPv6 interface identifier Prevent identification of traffic regardless of the prefix Initial value based on random number Future values based on MD5 hash of history value and EUI-64-based interface identifier  Result is a temporary address Generated from public address prefixes using stateless address autoconfiguration Changes over time

ZyXEL Confidential IPv6 Multicast Address FF...: Ethernet Multicast Address Mapping IPv6 Multicast Addresses to Ethernet Addresses

ZyXEL Confidential IPv6 Addresses Application Router 1 Subnet 2 Subnet 1 Router 2 Host A Host B Site: FEC0::1: 20D:60FF:FECB:6255 Link: FE80::20D:60FF:FECB:6255 Multicast: FF01::1 FF02::1 FF02::1:FFCB:6255 internet Global: 3000:4D:C00:: 20D:60FF:FECB:6255

ZyXEL Confidential Subnetting the IPv6 Address Space  Subnetting for NLA IDs [16-bit prefix]:00 fr s

ZyXEL Confidential Subnetting the IPv6 Address Space  Subnetting for SLA IDs [48-bit prefix]: :: f s r

ZyXEL Confidential Expression  Based on s (the number of bits chosen for subnetting), m (the prefix length of the network prefix being subnetted), and F (the hexadecimal value of the subnet being subnetted), calculate the following: f = m - 48 f is the number of bits within the subnet ID that are already fixed. n = 2s n is the number of network prefixes that are obtained. i = 216-(f+s) i is the incremental value between each successive subnet ID expressed in hexadecimal form. l = 48 + f + s l is the prefix length of the new subnetted network prefixes.

ZyXEL Confidential Example  To perform a 3-bit subnetting of the site- local network prefix FEC0:0:0:C000::/51, we first calculate the values of the number of prefixes, the increment, and the new prefix length. Our starting values are F = 0xC000, s = 3, and f = = 3. The number of prefixes is 8 (n = 23). The increment is 0x400 (i = 216-(3+3) = 1024 = 0x400). The new prefix length is 54 (l = ).

ZyXEL Confidential Q&A

ZyXEL Confidential DateSubjectLecturer Introduction to IPv6 IPv6 Addressing IPv6 Header & Extensions Neighbor Discovery Protocol Multicast Listener Discovery IPv6 Routing ICMPv6 Address Autoconfigurator Joe Zhao Milo Liu Joe Zhao Feng Zhou Billy Bian Jeffrey Zhou Feng Zhou Milo Liu 03/10 03/16 03/23 03/30 04/06 Training course arrangement

ZyXEL Confidential DateSubjectLecturer Setting Up an IPv6 Test Lab IPv6 Migration Mechanisms IPv6 Mobility Joe Zhou Milo Liu 04/13 04/20 Training course arrangement