Group members:- Himasweta pattanaik M.A.Sravni Liakat ali khan Agamani karmakar

P RESENTATION INCLUDES :- Ipv6 :- Advantages Packet format Extension header Transition Dual stack Tunneling Header translation Structure Address space Icmpv6(icmpv4):- Why Comparison Error reporting Query

A DVANTAGES :- larger address space better header format new options new options allowance for extension support for resource allocation support for more security

P ACKET FORMAT :- Each packet is composed of mandatory base header followed by the payload. Payload consist of two parts:- 1)optional extension header 2)data from upper layer

C ONTD … Base header:- base header consists of eight fields. Those are *version *priority *flow label *payload length *next header *hop limit *source address *destination address

P RIORITY :- This field defines the priority of each packet with respect to other packet from same source. If one of the two consecutive datagrams must be discarded then the datagram with lower packet priority will be discarded. Ipv6 divides traffic into two broad categories:- a)congestion controlled traffic b)non congestion controlled traffic

C ONGESTION CONTROLLED TRAFFIC :- If a source adapts itself to traffic slowdown when there is congestion, the traffic is referred as congestion controlled traffic. Tcp, which uses sliding window protocol can easily respond to traffic. Congestion controlled data are assigned priorities from 0 to 7. A priority of 0 is the lowest and a priority of 7 is highest.

Priorities for congestion-controlled traffic Priorities for congestion-controlled traffic

N ON - CONGESTION CONTROLLED :- Refers to a type of traffic that expects minimum delay. Discarding of packet is not desirable. Retransmission in most case is impossible Source does not adapt itself to congestion. Eg:- real time audio and video Priority number assigned from 8 to 15.

Priorities for noncongestion-controlled traffic

Comparison between IPv4 and IPv6 packet header

E XTENSION HEADER :- Length of base header is fixed at 40 bytes. To give greater functionality to IP datagram, the base header can be followed by up to 6 extension header. All the 6 headers are defined in the following dig.

(The transition) Transition strategy Dual stackTunneling Header translation

D UAL STACK :- All host should have dual stack of protocols before migrating completely to V-6 A station must run ipv6 and ipv4 simultaneously until all the internet uses ipv6. To determine which version to send while sending the a packet to a destination the source host queries the DNS.

T UNNELING :- This is used when two computers using ipv6 want to communicate with each other and the packet must pass through a region that uses ipv4. Packets must have ipv4 address. Ipv4 packet is carrying an ipv6 packet as data,the protocol value is set to 41.

H EADER TRANSLATION :- It is necessary when the majority of the internet has moved to ipv6 but some system still use ipv4. Sender wants to use ipv6, but the receiver does not understand it. Header format must be totally changed to header translation. Header of the ipv6 packet is converted to an ipv4 header.

Structure :- Ipv6 address consists of 16 bytes(octets);it is 128 bits long. Ipv6 address consists of 16 bytes(octets);it is 128 bits long. An IPv6 address is 128 bits long.

C ONTD … Abbreviation :- Leading 0’s can be dropped not the trailing 0’s

19.26 Type prefixes for IPv6 addresses:-

19.27 Type prefixes for IPv6 addresses (continued)

A DDRESS SPACE :- Unicast :- *single computer *packets must be delivered to specific computer. *divided into two categories 1) geographically based 2) provider based generally used by a normal host as a unicast address

Multicast :- *used to define a group of hosts instead of 1 *packets sent to a multicast address must be delivered to each member of the group * flag :- it defines either the group address is permanent or transient.

Any cast:- *like a multicast address, defines a group of nodes *packets delivered to only one member of the group, the one with shortest route. Local address

Reserved address

ICMPv6  Another protocol that has been modified in version 6 of the TCP/IP protocol suite is ICMP.  This new version, Internet Control Message Protocol version 6 ( ICMPv6 ), follows the same strategy and purposes of version 4.  ICMPv6, however, is more complicated than ICMPv4: some protocols that were independent in version 4 are now part of ICMPv6 and some new messages have been added to make it more useful.

34 Comparison of network layers in version 4 and version 6

Taxonomy of ICMPv6 messages

General format of ICMP messages

ERROR REPORTING MESSAGES  As we saw in our discussion of version 4, one of the main responsibilities of ICMP is to report errors.

38 Comparison of error-reporting messages in ICMPv4 and ICMPv6

Destination unreachable message

Packet-too-bit message

Time-exceeded message

Parameter-problem message

Redirection message format

. QUERY MESSAGES TCP/IP Protocol Suite 44

45 Table 27.8 Comparison of query messages in ICMPv4 and ICMPv6

Echo request and reply messages

Router-solicitation and advertisement message formats

Neighbor-solicitation and advertisement message formats

Group-membership messages

Group-membership message formats

Four situations of group-membership operation