Future Directions For IP Architectures Ipv6 Cs686 Sadik Gokhan Caglar

Contents Introduction Differences between IPv4 & IPv6 IPv6 Addressing Differences between IPv4 & IPv6 The additional headers Conclusion References

Introduction – IPv4 problems The recent exponential growth of the Internet and the exhaustion of IPv4 address space The ability of Internet backbone routers to maintain large routing tables

Introduction – IPv4 problems The need for simpler configuration The requirement for security at the IP level The need for better support for real-time delivery of data (QoS)

Introduction – IPv6 Features New header format Large address space Efficient and hierarchical addressing Built-in security Better support for QoS Extensibility

Differences between IPv4 & IPv6 32 bit addresses IPSec support optional Header includes a checksum Header includes options ARP frames are used for resolving addresses 128 bit addresses IPSec support required No checksum in header Optional data is moved to extension headers ARP is replaced by Neighbor solication messages

Differences between IPv4 & IPv6 Broadcast addresses are used to send traffic to all nodes in subnet Uses host addresses A, resource records in DNS to map host names to IP addresses Must support a 576 byte packet size (Possibly Fragmented) No broadcast address es are used. A multi- cast address is used Uses AAAA resource records in the DNS to map host names to IP addresses Must support a 1280 byte packet size without fragmentation

IPv6 Addressing Number of IPv4 addresses: 4,294,967,296 Number of IPv6 addresses: 340,282,266,920,938,463,463,374,607, 431,768,211,465 (or 3.4*10 38 ) For every square meter of earth there are 655,570,793,348,866,943,898,599 (6.5*10 23 )

IPv6 Syntax 128 bit addresses are divided into 16 bit blocks. The 16 bit blocks are converted to 4 digit hexadecimal numbers and separated by colons DA:00D3:0000:2F3B:02AA:00FF:FE28:9C5A

Zero Suppression And Compression Zero suppression: 21DA:00D3:0000:2F3B:02AA:00FF:FE28: 9C5A 21DA:D3:0:2F3B:2AA:FF:FE28:9C5A Zero compression: FE80:0:0:0:2AA:FF:FE9A:4CA2 FE80::2AA:FF:FE9A:4CA2

Types of IPv6 Addresses Unicast addresses: Identifies a single interface within the scope of the type unicast address. Multicast addresses: Identifies multiple interfaces. One to Many. Anycast addresses: Identifies multiple interfaces. One to One of Many.

Unicast Addresses TLA ID: Top level aggregator. The highest level in routing hierarchy. Res: Reserved for future use. NLA ID: Next level agg. Specific customer site. SLA ID: Site level agg. Identify subnets. Interface ID: Shows the interface on subnet.

Multicast Addresses Flags: Indicates the flags set on the multicast address. Scope: Indicates the scope of the IPv6 Internetwork which the traffic is intended. Group ID: Identifies the multicast group and is unique within the scope.

Anycast Addresses All router interfaces attached to a subnet are assigned the subnet-Router anycast address for that subnet.

IPv4 & IPv6 addresses Multicast addresses ( /4) Broadcast addresses Unspecified add. is Loopback add is Public IP address Private IP addresses DNS name resolution (A) resource record DNS reverse resolution: IN-ADDR.ARPA domain IPv6 multicast addresses (FF00::/8) N/A Unspecified address is :: Loopback address is ::1 Global unicast address Site local addresses DNS name resolution AAAA resource record DNS reverse resolution: IP6.INT domain or IP6.ARPA

IPv4 & IPv6 Headers

The Additional Headers ValueHeader 0Hop-by-Hop options head. 6TCP 17UDP 41Encapsulated IPv6 h. 43Routing header 44Fragmentation header 46RSVP header 50Encapsulating security payload 51Authentication header 58ICMPv6 59No next header 60Destination options head.

Hop-byHop Options Header Used to specify delivery parameters at each hop on the path to destination. Pad1 option: Insert a single byte of padding. PadN option: Insert 2 or more bytes. Jumbo Payload option: 4,294 kb > P > 65 kb Router Alert option: Multicast or RSVP.

Destination Options Header Used to specify packet delivery parameters for either intermediate destinations or final.

Routing Header Used to specify the route from source to destination.

Fragment Header

Authentication Header Provides Data authentication & anti-replay protection. SPI: Identifies a spesific IPSec SA. Sequence number: Anti-replay protection.

Encapsulating Security Header & Trailer ESP provides data confidentiality, data authentication and data integrity services for the payload.

ICMPv6 Header Type: Indicates the type of message. Error messages start with 1, info messages start with 0. Code: Differentiates among multiple messages. If there is only one message it is set to 0.

ICMPv6 Error Messages Destination unreachable Packet too big Time Exceeded Parameter Problem

ICMPv6 Informational Messages Echo request Echo reply Multicast Listener Query Multicast Listener Report Multicast Listener Done Neighbor discovery message

Conclusion The IPv6 helps to overcome some of the problems that IPv4 can’t such as: Provides a bigger address space Provides a fully hierarchical routing Provides a simpler configuration Provides security at IP level Provides a better QoS

References ipvers6.asp ml