IP Addressing Lecture # 1 Hassan Shuja 01/31/2006

IP Addressing What is it What is it –An IP address is an address used to uniquely identify a device on an IP network –An address is a 32-bit numeric address written as four numbers separated by periods –IPv4 is made up of 5 different classes Class A,B,C,D,E Class A,B,C,D,E –Class A,B,C are standard Internet and intranet routable addresses Private addresses are only intranet routable Private addresses are only intranet routable –Class D are Multicast addresses and class E are used for research

IP Addressing What is it What is it –IP addresses are used by routers to route packets to destinations

IP Addressing What is it What is it –An address is made up of a network portion and a host portion The network portion is used to identify the network The network portion is used to identify the network –Does not change within a network or subnetwork The host portion is the range of addresses assigned to nodes on the network The host portion is the range of addresses assigned to nodes on the network –Standard Network & Host portion of Class A,B,C Class Anh.h.h Class Anh.h.h Class Bn.n h.h Class Bn.n h.h Class Cn.n.n h Class Cn.n.n h

IP Addressing Obtaining IP Addresses Obtaining IP Addresses –IANA is the governing body for all IP addresses and has regional registry organizations American Registry for Internet Numbers (ARIN) supports North America region American Registry for Internet Numbers (ARIN) supports North America region –IANA requires justification before they allocate a range of IP addresses for somebody –Most IP addresses these days are obtained through ISPs

IP Addressing Subnet Mask Subnet Mask –A 32-bit value that is used to distinguish the network ID portion of the IP address from the host ID –Subnet Masks determines size of local subnet –Helps determine if two addresses are on the same network Default Gateway Default Gateway –Default Gateway handles requests that are destined for outside of the local subnet –The address of the router on the local subnet

IP Addressing Subnetting Subnetting –A Method use to break up large networks into smaller ones Splits the host field into a subnet and host section Splits the host field into a subnet and host section –This splitting is determined by the subnet mask The Network field remains unchanged The Network field remains unchanged –Subnetting allows for ease of administration, conservation of IP addresses, limit broadcast domains, and efficient use of resources Converting Decimal to Binary Converting Decimal to Binary – _1_2_5.pdf