Advanced Networking and

Applications

CST 451-1

Advanced Networking and

Applications

CST 451-1

Uva Wellassa University Badulla

Sri Lanka

ContentsContents

IP4 Problems of IP4 Network address translation IPV6 What’s Good about IP6 IPv6 address notation Types of addresses IPV4 address in IP6 IPv6 unicast IPv6 multicast IPv6 anycast IPv6 special address IPv6 ready applications Transition plan Migration to IPv6 Communication between ipv4 and IPv6

IPv4IPv4

Forth revision of development of Internet Protocol(IP) Most widely used protocol at present Connection-less protocol used on packet-switched Link

Layer networks A system of addresses

To identify devices 32 bits

• 232 combinations• Nearly 4.3 billion

Not enough and more addresses are needed

Problems of IPv4Problems of IPv4

1.Insuffieciency- Only four bytes

• Maximum nodes ~ 4.3 billion• Much less than the human population (6.799 billion)

- Not enough for growing number of users- Will be exhausted in near future

2.Increasing routing information

- Rapid growth of routing tables in backbones

3. Increasing the number of Network Address Translation (NAT)

- Breaking the Internet architecture

Problems of IPv4Problems of IPv4

4.Security issues

- Number of ways to encrypt IPv4 traffic

• Example: IPSec

- No real standard encryption method

5.Real-time delivery of multimedia content and necessary bandwidth allocation Quality of Service (QoS) Different interpretations QoS compliant devices are not compatible one another

Network Address Translation(NAT)Network Address Translation(NAT)

Allows to maintain public IP addresses and private IP addresses separately

Also used in server load balancing

This operates in side the router

Maintains an address pool

First the destination is checked

The address is translated

The network address information in the datagram is modified

How NAT works???How NAT works???

NAT

IPv6IPv6 Next development version of Internet protocol Address size is 128 bits IPv6 address representation

xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx Each x is a 4bit hexadecimal digit IPv6 addresses range from

0000:0000:0000:0000:0000:0000:0000:0000 to

ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff.

IPv6IPv6

Two other formats Omit leading zeros

• Specify IPv6 addresses by omitting leading zeros• E.g. : 1050:0000:0000:0000:0005:0600:300c:326b can be

written as 1050:0:0:0:5:600:300c:326b

Double colon • Specify IPv6 addresses by using double colons (::) in place

of a series of zeros• E.g. : ff06:0:0:0:0:0:0:c3 may be written as ff06::c3• Double colons can be used only once in one IP address

What’s Good about IPv6?What’s Good about IPv6?

Bigger address space 128 bits for addressing No NATs are needed Allows full IP connectivity

• For Computers, Mobile devices

Mobility Facility for mobile devices Allows roaming between different networks

What’s Good about IPv6?What’s Good about IPv6?

Built-in security Includes Ipsec

• Authentication• Encryption• Compression

IPv6 address notationIPv6 address notation

Three possible notation types Depends on content of address you need represent

1.Standard notation - Represent the address as eight 16-bit hexadecimal words separated by ``:'' (colons)

- E.g : FEDC:BA98:0332:0000:CF8A:000C:2154:7313 or

FEDC:BA98:332:0:CF8A:C:2154:7313.

2.Compressed notation - Multiple fields of zeros

- Represent a single contiguous group of zero fields within an IPv6 address

- Uses a double colon``::‘’

- E.g.: 1762:0:0:0:0:B03:1:AF18 FF01:0:0:0:CA:0:0:2 0:0:0:0:0:0:0:1:0:0:0:0:0:0:0 can be represented as

1762::B03:1:AF18 FF01::CA:0:0:2 ::1 ::

IPv6 address notationIPv6 address notation

Mixed notation For IPv4 addresses encapsulated in IPv6 addresses Represented using the original IPv4 ``.'' notation

• 0:0:0:0:0:0:127.32.67.15 • 0:0:0:0:0:FFFF:127.32.67.15

Possible to use the compressed notation• ::127.32.67.15• ::FFFF:127.32.67.15

Types of addressesTypes of addresses

unicast communicate specified 1 computer

multicast communicate group of computers

anycast send group address that can receive multiple computers,but

receive 1 computer

sg

gd s

g

a

as

a

unicast anycastmulticast

IPv4 address in IPv6IPv4 address in IPv6

IPv6 site is island surrounded IPv4 ocean connect IPv6 island each other

encapsulate IPv6 packet in IPv4 packet threat as IPv4 as data link layer

IPv4 oceanIPv6 site

IPv6 site

IPv6 siteIPv6 in IPv4 packet

IPv6 in IPv4 TunnelIPv6 in IPv4 Tunnel

IPv6 Site

IPv6 Site

IPv6 Site

IPv4 Internet

IPv6 UnicastIPv6 Unicast

To transmit data from one point to another. Multiple users might request

Same data From the same server At the same time

duplicate data streams are transmitted one to each user

Scope may be Global or Local Global for worldwide communication Local for communication within a site

Server

Router

Ethernet Switch

Figure 01: How unicast works

IPv6 multicastIPv6 multicast

Ability to send a single packet to multiple destinations No broadcast

Ability to send a packet to all hosts on the attached link same effect can be achieved by sending a packet to the link-

local all hosts multicast group

Applications Telephony and video conference Database simultaneous update Parallel computing Real time news

Figure 02: How multicast works

Server

Router

Ethernet Switch

IPv6 anycastIPv6 anycast

Uses Anycast address Identifies a set of nodes Packet will reach only one out of many (usually, topologically

closest one)

Anycast address can be assigned to routers only Anycast address cannot be used as a source

IPv6 special addressesIPv6 special addresses

Four basic types of "special" IPv6 addresses reserved private loopback unspecified.

Reserved Addresses Reserved block is at the “top” of the address space: Starting with “0000 0000”

• Private Addresses Called local-use addresses or link-layer addresses. No NATs So local-use addresses are intended for communication inherently

designed only to be sent to local devices.

IPv6 special addressIPv6 special address

Loopback Address A special loopback address for testing Datagrams sent to this address “loop back” to the sending

device The loopback address is 0:0:0:0:0:0:0:1or as “::1” Ping ::1

• Should answer myself

IPv6 ready applicationsIPv6 ready applications

Handles  ":"  in  address  correctly Handles  IPv4  and  IPv6  addresses

% ftp ftp.kame.net % ftp 3ffe:501:4819:2000:5254:ff:fedc:50d2

Transition planTransition plan

Current status Only IPv4

Phase I IPv4/v6 Dual node IPv4 address in IPv6 address format IPv6 tunneling on the IPv4 Network

Phase II Combination of IPv6 infrastructure and IPv4

infrastructure Translate between IPv4/v6 each other(optional) More IPv6 nodes

Migration to IPv6Migration to IPv6

dual stack Involves running IPv4 and IPv6 at the same time End nodes and routers/switches run both protocols

Tunnel To carry one protocol inside another Take IPv6 packets and encapsulate them in IPv4

packets to be sent across portions of the IPv4 networks

Translator Protocol translation (NAT-PT) simply translate IPv6

packets into IPv4 packets.

Figure 03 Two popular Migration Strategies

Communication between IPV4 and IPv6Communication between IPV4 and IPv6

IPv6/IPv4-dual(IPv4 compat. addr.)

IPv6-only (IPv4 compat. addr.)

translationrouter

IPv6-only (IPv6 addr.)

IPv4-only

IPv4-only

IPv4-only TCPrelay