IPv4 and IPv6

Rishav Bhurtel0307 A

• an identifier for a particular machine on a particular network.

• The network portion of the IP address is allocated to internet service provider(ISP), under authority of the Internet Assigned Number Authority (IANA).

• Which section of the IP address represent the network & which sections represent the machine will depend on what “class” of IP address is assigned to a network.

IPV4

• Internet Protocol version 4 (IPv4) is the fourth version of the Internet Protocol (IP). It is one of the core protocols of standards-based internetworking methods in the Internet• 32 bits• 2^32 = 4,294,967,296• IPv4 is a connectionless protocol for use on packet-switched

networks.

IPv4 Addressing• The 32-bit IP address is grouped eight bits at a time, separated by dots,

and represented in decimal format (known as dotted decimal notation). Each bit in the octet has a binary weight (128, 64, 32, 16, 8, 4, 2, 1). The minimum value for an octet is 0, and the maximum value for an octet is 255.The figure below illustrates the basic format of an IP address.

IPv4 Address Scheme :• An IP packet contains several types of information, as

illustrated.

• Version---Indicates the version of IP currently used. · IP Header Length (IHL)---Indicates the datagram header length in 32-bit words. · Type-of-Service---Assigns datagrams various levels of importance. · Total Length---Specifies the length, in bytes, of the entire IP packet. · Identification---Contains an integer that identifies the current datagram. · Flags---The two low-order (least-significant) bits control fragmentation. The low-order

bit specifies whether the packet can be fragmented. The middle bit specifies whether the packet is the last fragment in a series of fragmented packets. The third or high-order bit is not used.

· Fragment Offset---Indicates the position of the fragment's data relative to the beginning of the data in the original datagram.

· Time-to-Live---Maintains a counter that gradually decrements down to zero, at which point the datagram is discarded. This keeps packets from looping endlessly.

· Protocol---Indicates which upper-layer protocol receives incoming packets after IP processing is complete.

· Header Checksum---Helps ensure IP header integrity. · Source Address---Specifies the sending node. · Destination Address---Specifies the receiving node. · Options---Allows IP to support various options, such as security. · Data---Contains upper-layer information.

• IPv4 uses 32-bit addresses for Ethernet communication in five classes, named A, B, C, D and E.

Private addresses to assign within a network

(Not globally routable)

In its simplest configuration, the Network Address Translator (NAT) operates on a router connecting two networks together; one of these networks (designated as inside) is addressed with either private or obsolete addresses that need to be converted into legal addresses before packets are forwarded onto the other network (designated as outside). The translation operates in conjunction with routing, so that NAT can simply be enabled on an Internet access router when translation is desired.

Schema diagram:

IPv6

• Pv6 (Internet Protocol version 6) is a set of specifications from the Internet Engineering Task Force (IETF) that's essentially an upgrade of IP version 4 (IPv4). • 32 bits to 128 bits. • 2^128 = 340,282,366,920,938,463,463,374,607,431,768,211,456• And a new type of address called an "anycast address" is defined,

used to send a packet to any one of a group of nodes. • Authentication and Privacy Capabilities Extensions to support

authentication, data integrity, and (optional) data confidentiality are specified for IPv6.

IPv6 Address Scheme :• An IP packet contains several types of

information, as illustrated.

• Version (4-bits): It represents the version of Internet Protocol, i.e. 0110.

• Traffic Class (8-bits): These 8 bits are divided into two parts. The most significant 6 bits are used for Type of Service to let the Router Known what services should be provided to this packet. The least significant 2 bits are used for Explicit Congestion Notification (ECN).

• Flow Label (20-bits): This label is used to maintain the sequential flow of the packets belonging to a communication. The source labels the sequence to help the router identify that a particular packet belongs to a specific flow of information. This field helps avoid re-ordering of data packets. It is designed for streaming/real-time media.

• Payload Length (16-bits): This field is used to tell the routers how much information a particular packet contains in its payload. Payload is composed of Extension Headers and Upper Layer data.

• Next Header (8-bits): This field is used to indicate either the type of Extension Header, or if the Extension Header is not present

• Hop Limit (8-bits): This field is used to stop packet to loop in the network infinitely. This is same as TTL in IPv4. The value of Hop Limit field is decremented by 1 as it passes a link (router/hop). When the field reaches 0 the packet is discarded.

• Source Address (128-bits): This field indicates the address of originator of the packet.

• Destination Address (128-bits): This field provides the address of intended recipient of the packet.

IPV6 addressThe 128-bit IP address is represented as 8 groups of 4 hexadecimal digits, each group representing 16 bits (2 octets). The groups are separated by colons(:). The minimum value for an octet is 0, and the maximum value for an octet is F. The figure below illustrates the basic format of an IP address.

difference between IPv4 and IPv6S.N IPv4 IPv6

1. Addresses are 32 bits (4 bytes) long. Addresses are 128 bits (416 bytes) long.

2. Both routers & sending host fragment the packets.

Routers don’t fragment the packets but sending host fragment the packets.

3. Header includes a checksum. Header doesn’t includes a checksum.

difference between IPv4 and IPv6 cont…S.N IPv4 IPv6

4. Classes of addressing are A, B, C, D, E. Classes of addressing are unicast, anycast, multicast.

5. Configure either manually or through DHCP. Doesn’t require manual configuration.

6. Must support a 576 byte packet size. Must support 1208 byte packet size.

difference between IPv4 and IPv6 cont…S.N IPv4 IPv6

7. IPv4 address uses the dot-decimal notation. IPv6 address are represented in a hexadecimal, colon-separated notation.

8. Not suitable for mobile networks. IPv6 is better suited to mobile networks.

9. Address space is small (232). Larger address space (2128).

difference between IPv4 and IPv6 cont…S.N IPv4 IPv6

10. Internet protocol security(IPSec) is mandatory in this.

IPSec is optional.

11. An IP address is made up of 4 bytes of information expressed as 4 number between 0 & 255 shown separated by periods.e.g.- 238.17.159.4

An IPv6 address is represented by 8 group of 16 bit hexadecimal values separated by colons (:).e.g.- 2001:0db8:85a3:0000:0000:8a2e:0370:7334

• What's Next? IPv7?• Even with 20 years of TCP networks UUCP still exists• IPv6 to IPv4 NAT is just an interim solution, will not work with all

protocols.

Thank You!