Network Layer (part2)6-1 INT-201: Computer Network and Communication System อ. ดร. ภัทร ลีลาพฤทธิ์ Dr. Pattara Leelaprute Computer Engineering Department Kasetsart University Computer Networking: A Top Down Approach, 4 th edition. Jim Kurose, Keith Ross Addison-Wesley, July Special Module: IP address

Network Layer (part2)6-2 Internet Address

Network Layer (part2)6-3 Internet Classes Classfull Addressing

Network Layer (part2)6-4 IP Address Class

Network Layer (part2)6-5 No. of Network / Host

Network Layer (part2)6-6 IP address in decimal notation xxxx x xxx = 158

Network Layer (part2)6-7 IP address practice #1 #2 #3

Network Layer (part2)6-8 IP address in decimal notation

Network Layer (part2)6-9 Class ranges of Internet Address

Network Layer (part2)6-10 IP Address Class A 50% B 25% C 12.5% D E

Network Layer (part2)6-11 IP Addressing: introduction r IP address: 32-bit identifier for host, router interface r interface: connection between host/router and physical link m router’s typically have multiple interfaces m host typically has one interface m IP addresses associated with each interface =

Network Layer (part2)6-12 Subnets r IP address: m subnet part (high order bits) m host part (low order bits) r What’s a subnet ? m device interfaces with same subnet part of IP address m can physically reach each other without intervening router network consisting of 3 subnets subnet

Network Layer (part2)6-13 Subnets / / /24 Recipe r To determine the subnets, detach each interface from its host or router, creating islands of isolated networks. Each isolated network is called a subnet. Subnet mask: /24

Network Layer (part2)6-14 IP addressing: CIDR CIDR: Classless InterDomain Routing m subnet portion of address of arbitrary length m address format: a.b.c.d/x, where x is # bits in subnet portion of address subnet part host part /23