Internet Protocols

IPv4 and IPv6

Learning objectives :

▪ What is a Network Address?

▪ What is an IP?

▪ What are frames and Packets ?

▪ What is the scope of IP ?

▪ How are IPv4 and IPv6 different ?

Network Address

▪ A network address serves as a unique identifier for a computer on a network.

▪ When set up correctly, computers can determine the addresses of other computers on the network and use these addresses to send messages to each other.

▪ One of the best known form of network addressing is the Internet Protocol (IP) address. IP addresses consist of four bytes (32 bits) that uniquely identify all computers on the public Internet.

▪ Another popular form of address is the Media Access Control (MAC) address. MAC addresses are six bytes (48 bits) that manufacturers of network adapters burn into their products to uniquely identify them.

What is Internet Protocol?

▪ Internet Protocol is a set of technical rules that defines how computers communicate over a network.

▪ There are currently two versions: IP version 4 (IPv4) and IP version 6 (IPv6).

IP Frames IP Packets

▪ IP packets are carried over link-layer technologies such as Ethernet (10 Mbps), Fast Ethernet (100 Mbps), Gigabit Ethernet (1000 Mbps), Frame Relay, and many others.

▪ Each link-layer technology family has its own link-layer frame that carries IP packets.

▪ IP packet is carried between the frame header and frame trailer of a link-layer frame.

▪ An IP packet has two fundamental components:

1. IP header ▪ IP header contains many fields

that are used by routers to forward the packet from network to network to a final destination.

▪ Contains layer 3 info ▪ Fields within the IP header

identify the sender, receiver, and transport protocol and define many other Parameters.

2. Payload ▪ Represents the information

(data) to be delivered to the receiver by the sender.

▪ Contains data & upper-layer info

IP addresses

There are two parts of an IP address:

▪ Network ID

▪ Host ID

The various classes of networks specify additional or fewer octets to designate the network ID versus the host ID.

Scope of IP with the OSI Reference Model

What is IPv4?

▪ First version of Internet Protocol to be widely used &accounts for most of today’s Internet traffic

▪ IPv4, defines a 32-bit address - 232 (4,294,967,296) IPv4 addresses available

▪ There are just over 4 billion IPv4 addresses.

▪ The first problem is concerned with the eventual depletion of the IP address space.

▪ Traditional model of classful addressing does not allow the address space to be used to its maximum potential.

What is IPv6?

▪ IPv6 is a newer numbering system that provides a much larger address pool than IPv4.

▪ It was deployed in 1999 and should meet the world’s IP addressing needs well into the future.

Why IPv6?

▪ To provide a larger address space requirements

▪ Introduction of new services : Integration Multicast Quality of Service Security Mobility (MIPv6)

▪ Stateless Address Auto-configuration

▪ Aggregation based address hierarchy- efficient backbone routing

▪ Support for resource allocation, more security and mobility

IPv6

3FFE:085B:1F1F:0000:0000:0000:00A9:1234

8 groups of 16-bit hexadecimal numbers separated by “:”

Leading zeros can be removed

3FFE:85B:1F1F::A9:1234

:: = all zeros in one or more group of 16-bit hexadecimal numbers

Difference between Ipv4 and Ipv6

▪ The technical functioning of the Internet remains the same with both versions

▪ It is likely that both versions will continue to operate simultaneously on networks well into the future.

▪ To date, most networks that use IPv6 support both IPv4 and IPv6 addresses in their networks.

IPv4 Address IPv6 Address

Address Length – 32 bits 128 bits

Address Representation -

decimal

hexadecimal

Internet address classes Not applicable in IPv6

Multicast addresses (224.0.0.0/4) IPv6 multicast addresses

(FF00::/8)

Broadcast addresses Not applicable in IPv6

Unspecified address is 0.0.0.0 Unspecified address is ::

Loopback address is 127.0.0.1 Loopback address is ::1

Public IP addresses Global unicast addresses

Private IP addresses (10.0.0.0/8,

172.16.0.0/12, and

192.168.0.0/16)

Site-local addresses (FEC0::/10)

Autoconfigured addresses

(169.254.0.0/16)

Link-local addresses (FE80::/64)

Difference between Ipv4 and Ipv6

IPv4 Address IPv6 Address

Text representation: Dotted decimal notation Text representation: Colon hexadecimal format with

suppression of leading zeros and zero compression.

IPv4-compatible addresses are expressed in dotted

decimal notation.

Network bits representation: Subnet mask in dotted

decimal notation or prefix length

Network bits representation: Prefix length notation

only

DNS name resolution: IPv4 host address (A)

resource record

DNS name resolution: IPv6 host address (AAAA)

resource record

DNS reverse resolution: IN-ADDR.ARPA domain DNS reverse resolution: IP6.ARPA domain

Text representation: Dotted decimal notation Text representation: Colon hexadecimal format with

suppression of leading zeros and zero compression.

IPv4-compatible addresses are expressed in dotted

decimal notation.

Doubts ?

“The important thing is not to stop questioning”

-Albert Einstein