ISO 9001:2008. Pankaj Kumar Dir, TEC, DOT

Transcription

1 ISO 9001:2008 Pankaj Kumar Dir, TEC, DOT

2 AWARENESS OBJECTIVES IPv6 Address Format & Basic Rules Understanding the IPv6 Address Components Understanding & Identifying Various Types of IPv6 Addresses 3/25/2012 2

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4 IPv4 Address SYNTAX W. X. Y. Z W,X,Y,Z represent 8 bits converted to Decimal IPv6 Address SYNTAX XXXX : XXXX : XXXX : XXXX : XXXX : XXXX : XXXX : XXXX Where each x represent a 4 bits hexadecimal field 2001:0DB8:1234:0000:0000:C1C0:ABCD:0876

5 FROM 128 BIT BINARY TO 8 BLOCK OF HEXTETS The following is an IPv6 address in binary form: The 128-bit address is divided along 16-bit blocks: Each 16-bit block is converted to hexadecimal taking 4 bits as one block- and delimited with colons. The result is : Second 16 bits block is D B 8 Thus, the 8 blocks are represented as : 2001:0DB8:0000:2F3B:02AA:00FF:FE28:9C5A

6 IPv6 IPv6 Address Capacity IPv4: 32 bits or 4 bytes long 4.2 billion possible IP addresses IPv6: 128 bits or 16 bytes 340* possible IP addresses 340 undecillion or 340 trillion trillion trillion 340 lakh lakh lakh crores!!

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8 RULE 1 It is Case Insensitive colon hextet notation 2001:0DB8:0000:003B:02AA:00FF:FE28:0C5A 2001:0Db8:0000:003B:02aa:00ff:FE28:0C5A

9 Rule 2 The leading zeros within each 16-bit block can be removed. However, each block must have at least a single digit 2001:0Db8:0000:003B:02aa:00ff:FE28:0C5A 2001:0Db8:0000:003B:02aa:00ff:FE28:0C5A 2001:Db8:0:3B:2aa:ff:FE28:C5A 3/25/2012 9

10 RULE 3 SUPPRESSION OF CONTIGUOUS SEQUENCE OF 0 A contiguous sequence of 16-bit blocks set to 0 in the colon hexadecimal format can be compressed to ::, double-colon FF02:0:0:0:0:0:0:1 FF02::1 FE80:0:0:0:2AA:FF:FE9A:4CA2 FE80::2AA:FF:FE9A:4CA2 Zero compression can only be used once in a given address 2001:0:0:1234:0:0:0:C1C0 2001::1234::C1C0 3/25/

11 IPv6 Addresses in URL In a URL, it is enclosed in brackets If writing Domain name in the URL, Should use Fully Qualified Domain Names (FQDN)

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14 2001:0A3C:5437:ABCD:0:0:0:0/64 Prefix Interface ID 3/25/

15 IPv6 Prefixes Certain fixed numbers of high-order bits of an IPv6 address may specify an ISP Network, a site within an organisation or a subnet Prefixes for IPv6 Addresses are expressed in the same way as CIDR notation in IPv4. An IPv6 prefix is written in /N-length notation; N -Decimal For example, 21DA:D3::/48 and 21DA:D3:0:2F3B::/64 ; /48 AND /64 are IPv6 address prefixes.

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17 IPv6 Interface Identifiers Fixed Sixty-four LSB bits of IPv6 address. Guaranteed unique on the subnet In IPv4, hosts ID are of variable length depending upon the sub netting scheme whereas in IPv6 Interface ID is of fixed length as 64 bits Mapping IEEE bit MAC address into 64 bit Interface ID (EUI-64) In IPV6 nodes can generate its Interface ID automatically

18 Mapping IEEE 802 MAC address into interface identifier 48 bit MAC ID Insert FF FE Invert the 7 th bit

19 UNICAST MULTICAST ANYCAST 3/25/

20 IPv6 IPv6 Address scope Link-local: The scope is the local link (nodes on the same subnet) Site-local: The scope is the site of an organization (private site addressing) Now Deprecated Unique Local : Scope is the organization ; Similar to Private IPv4 addresses Global: The scope is global (IPv6 public addresses)

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22 Unicast IPv6 Addresses Global Link-local Unique-Local

23 Global Unicast Addresses Global unicast addresses are equivalent to public IPv4 addresses. They are globally routable and reachable on the IPv6 portion of the Internet Format Prefix 2000::/3 First 3 bits (001) are fixed; next 45 bit prefix- collection of larger and smaller ISPs that provide access to the IPv6 Internet Next 16 bits- Collection of subnets within an organization s site The interface ID 64 bit- identifies a specific interface on a subnet within an organization s site

24 001 First 3 bits are Reserved IANA has only released 1/8 th of the entire IPv6 addresses For this, first 3 MSB are fixed as 001 The entire global-unicast IPv6 address range is from 2000::/128 to 3FFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF/128, which is only 1/8th of the entire IPv6 address space!

25 Global Unicast Address Allocation IETF RFC 3177 recommended /48 block to end sites However, RIRs adopted /56 or /64 blocks Now IETF released RFC 6177, which allows flexibility to the RIRs in allocation of address block to end sites But it recommends blocks larger than /64 so that end sites may grow into multiple subnet. Top level ISP gets /30 or /32

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27 IPv6 IPv6 Link Local Unicast Address (LLA) Hosts on the same link (the same subnet) use these automatically configured addresses to communicate with each other. Must for the Neighbor Discovery protocol The prefix Format for LLA is FE80::/64. The prefix Format for LLA

28 IPv6 IPv6 Unique Local Address (ULA) Replaces Site Local Addresses Equivalent to Private IP addresses in IPv4 Provides unique Private IPv6 addresses across all sites of an organization Removes The ambiguity of non- unique site-local addresses in an organization The Format prefix for ULA is FC00::/7. The Prefix

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30 Special Unicast Addresses Unspecified address 0:0:0:0:0:0:0:0 or :: ( in IPv4) is only used to indicate the absence of an address The unspecified address is typically used by the node to know its address when plugged into the network. Loopback address 0:0:0:0:0:0:0:0:1 or ::1 ( in IPv4) used to identify a loopback interface, enabling a node to send packets to itself

31 Compatibility Addresses IPv4-compatible address 0:0:0:0:0:0:w.x.y.z or ::w.x.y.z where w.x.y.z is the dotted decimal representation of an IPv4 address used by hosts that are communicating with IPv6 over an IPv4 network IPv4-mapped address 0:0:0:0:0:ffff:w.x.y.z or ::ffff:w.x.y.z used to map IPv4 devices that are not compatible with IPv6 into the IPv6 address space

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33 MULTICAST ADDRESS One to many communication IPv6 nodes can listen to multiple multicast addresses at the same time No Broadcast Address in IPv6 IPv6 Multicast address Format Prefix FF00::/8

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35 Anycast IPv6 Addresses One-to-nearest Anycast addresses allow packet to be routed to one of a number of different nodes all responding to the same address are allocated from the unicast address space It cannot be distinguished from a Unicast address Used only as Destination Address and may be assigned to an IPv6 router only

36 Anycast IPv6 Address Uses Multiple Router on a remote subnet Multi Homing Multiple DNS server on a subnet Content delivery Networks IPv4 to IPv6 transition 6 to4 networks

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38 Address Auto Configuration Unique feature of IPv6 enabling automatic configuration of various types of IPv6 address by the IPv6 host By default IPv6 host can configure Link local address FE80::EUI-64 Interface ID Site local and Global IPv6 address can also be configured automatically without the help of DHCP server

39 Why does this matter? Manual configuration of individual machines before connecting them to the network may not be required. Only the Router & Server require Manual configuration Provide Plug-and-play communication A large site with multiple networks and routers should not require the presence of a statefull address configuration server. Enables small sensors to work in IPv6 network It may be one of the killer feature of IPv6

40 Hence, to Summarise IPv6 address is 128 bit long written in eight block of hexadecimal field Almost Infinite numbers of IPv6 addresses IPv6 address HAS TWO PART Routing prefix and Interface Identifier Unicast, Multicast, Anycast IPv6 Addresses with specific format prefix Nodes can auto configure IPv6 addresses

41 gkf nzd / ku; okn

42 RECALL BY TRYING THIS Match the following A. Link local address prefix i. FF00::/8 B. Unique local address prefix ii. FE80::/64 C. Multicast address Prefix iii. 2001::/3 D. Global address prefix iv. FD00::/8

43 IPv6 Address Planning: BSNL BSNL got 2001:4490::/30 from APNIC for IPv6 Implementation /30 is divided into four /32 blocks Only one /32 block planned for use now /32 block is divided into sixteen /36 blocks; each block for different services Example : Mobile : /38 to each zone ; /39 post paid /39 pre-paid

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45 IPv6 Interface Identifiers Fixed Sixty-four LSB bits of IPv6 address. Guaranteed unique on the subnet In IPv4, hosts ID are of variable length depending upon the sub netting scheme whereas in IPv6 Interface ID is of fixed length as 64 bits Essentially same as EUI-64 Mapping IEEE 802 MAC address into interface identifier Randomly generated interface identifier to provide a level of anonymity

46 INTERFACE ID : ILLUSTRATION

47 Mapping IEEE 802 MAC address into interface identifier EUI-64 from MAC addresses: MAC Address : D IPv6 Interface ID : 0202:2dff:fe02:8234 The Rules : Insert FFFE after the first 3 octets Last 3 octets remain the same Invert the 7 TH bit from the left of the first octet. Universal/local bit

48 EUI-64 Mapping Illustration

49 Stateless Types of Address Autoconfiguration Configuration of addresses is based on the receipt of Router Advertisement messages which provides prefix Prefix + Interface Id = IPv6 address Stateful Configuration is based on the use of a stateful address configuration protocol such as DHCPv6 to obtain addresses and other configuration options Both IP address is stateless configured but other configurations are stateful

50 Process of Stateless Autoconfiguration Auto configure link local address Verifies its uniqueness Neighbour solicitation & Neighbour Advertisement Obtain prefix and other information from Router Router solicitation and Router Advertisement Configure Global IPv6 address by combining Link Prefix with Interface ID Verify its uniqueness Duplicate Address Detection

51 STATELESS AUTO CONFIGURATION : ILLUSTRATION Global Address=Link Prefix + EUI 64 Address Router Address is the Default Gateway

52 IPv6 Stateless Autoconfiguration Example MAC address : 00:2C:04:00:FF:56 EUI 64 Address: 022C:04FF:FE00:FF56 Auto configured Link Local Address : FE80::22C:04FF:FE00:FF56 Link Prefix 2001:690:1:1 Configured Global IPv6 Address 2001:690:1:1:22C:04FF:FE00:FF56

53 Finally Try This One MAC Address : 00:08:C7:1B:8C:02 Router IP address : 2001:3452:4952:2837:: Find the auto configured IPv6 address by the host on this link

54 IPv6 IPv6 Address Types Unicast Address is for a single interface. IPv6 has several types (for example, global and IPv4 mapped). Multicast One-to-many Enables more efficient use of the network Uses a larger address range Anycast One-to-nearest (allocated from unicast address space). Multiple devices share the same address. All anycast nodes should provide uniform service. Source devices send packets to anycast address. Routers decide on closest device to reach that destination. Suitable for load balancing and content delivery services.

55 STRUCTURE OF IPv6 MULTICAST ADDRESS IPv6 Multicast address Format Prefix FF00::/8 Flag :Only the LSB flag is defined : 0 Permanently Assigned; 1- transient Scope Indicates the scope of the IPv6 internetwork for which the multicast traffic is intended The most prevalent values for the Scope field are 1 (interface-local scope), 2 (link-local scope), 5 (site-local scope), 8 (Organisation local), and E (Global)

56 1 all-nodes 2 all-routers

57 IPv6 Neighbor Discovery IPv6 nodes which share the same physical medium (link) use Neighbor Discovery (NDP) to: Discover their mutual presence Determine link-layer addresses of their neighbors (equivalent to ARP) Find routers Maintain neighbors reachability information Uses Multicast Address

58 IPv6 Neighbor Discovery Protocol features: Router discovery Prefix(es) discovery Parameters discovery (link MTU, Max Hop Limit,...) Address auto-configuration Address resolution Next Hop determination Neighbor Unreachability Detection Duplicate Address Detection Redirect

59 IPv6 Neighbor Discovery It provides the functionality of: ARP ICMP redirect

60 IPv6 Neighbor Discovery ND specifies 5 types of ICMP packets: Router Advertisement (RA) : Periodic advertisement (of the availability of a router) which contains:»list of prefixes used on the link (autoconf)»a possible value for Max Hop Limit (TTL of IPv4)»value of MTU Router Solicitation (RS) : The host needs RA immediately (at boot time)

61 IPv6 Neighbor Discovery Neighbor Solicitation (NS):»to determine the link-layer address of a neighbor»or to check its reachability»also used to detect duplicate addresses (DAD) Neighbor Advertisement (NA):»answer to a NS packet»to advertise the change of physical address Redirect:»Used by a router to inform a host of a better route to a given destination

62 IPv6 6/4 Dual Stack Hosts and Network This allows all the end hosts and intermediate network devices (like routers, switches, modems etc.) to have both IPv4 and IPv6 addresses and protocol stack. If both the end stations support IPv6, they can communicate using IPv6; otherwise they will communicate using IPv4. This will allow both IPv4 and IPv6 to coexist and slow transition from IPv4 to IPv6 can happen.

63 IPv6 6/4 Dual Stack Hosts and Network

64 IPv6 6/4 Dual Stack Hosts and Network IITK_KNPR_CMTR_DIA#sh run Building configuration... interface GigabitEthernet0/1 description Connected to IITK ip address ipv6 address 2001:DF0:92::1/64 ipv6 enable! interface GigabitEthernet0/2 description Airtel IPv6 Connectivity ip address ipv6 address 2404:A800:2:D::2/64 ipv6 enable!

65 IPv6 Tunneling IP6 via IP4 This allows encapsulating IPv6 packets in IPv4 Datagram for transport over IPv4 only network. This will allow IPv6 only end stations to communicate over IPv4 only networks.

66 IPV6 Address SYNTAX XXXX : XXXX : XXXX : XXXX : XXXX : XXXX : XXXX : XXXX Where each x represent a 4 bits hexadecimal field 2001:0000:1234:0000:0000:C1C0:ABCD:0876 X : x : x : x : x : x : x : x Each X Represent 16 Bits converted in Hexadecimal 3/25/

67 IPv6 IP6-IP4 Translation This allows communication between IPv4 only and IPv6 only end stations. The job of the translator is to translate IPv6 packets into IPv4 packets by doing address and port translation and vice versa.

68 IPv6 IPv6 Site Local Unicast Address IPv6 unicast site-local addresses are similar to IPv4 private addresses. The scope of a site-local address is the inter-network of an organization s site. The prefix for site-local addresses is FEC0::/48. RFC 3879 formally deprecates the use of site-local addresses for future IPv6 implementations Structure of a site-local address.