Internet Protocol(工P IP Addressing: introduction Part of tcp/Ip IP address: 32-bit Used by the Internet identifier for ho Specifies interface with higher layer router interface 孕12 e.g. TCP 223.1.13223 Only protocol at Layer 3 and physical lin Fundamental in suite a Defines host may have multiple 223.1.3.1 Internet addressing 地趣 Internet packet format Internet routing ce. not host IP Addressing IP Addressing Octet (8 bits). Octet (8 bits). Octet (8 bits) host part(low order bits) a what's a network 2 (from IP address device interfaces with 192 twork part of IP ddress can physically reach each intervening router est 24 bits are network address) IP Addressing 工 P Addresses How to find the given notion of"network", lets re-examine IP networks? 2231.1.3 Detach each interface from router host 22.2525 create " islands of isolated 2318 D1110 multicast address 223.1. 量2哑 1010 哈工大计算机学院 李全龙 Network Application Development 1: Introduction 55 Internet Protocol (IP) „ Part of TCP/IP „ Used by the Internet „ Specifies interface with higher layer „ e.g. TCP „ Only protocol at Layer 3 „ Fundamental in suite „ Defines „ Internet addressing „ Internet packet format „ Internet routing 哈工大计算机学院 李全龙 Network Application Development 1: Introduction 56 IP Addressing: introduction „ IP address: 32-bit identifier for host, router interface „ interface: connection between host, router and physical link „ router’s typically have multiple interfaces „ host may have multiple interfaces „ IP addresses associated with interface, not host, router 223.1.1.1 223.1.1.2 223.1.1.3 223.1.1.4 223.1.2.9 223.1.2.2 223.1.2.1 223.1.3.1 223.1.3.2 223.1.3.27 223.1.1.1 = 11011111 00000001 00000001 00000001 223 1 1 1 哈工大计算机学院 李全龙 Network Application Development 1: Introduction 57 IP Addressing 哈工大计算机学院 李全龙 Network Application Development 1: Introduction 58 IP Addressing „ IP address: „ network part (high order bits) „ host part (low order bits) „ What’s a network ? (from IP address perspective) „ device interfaces with same network part of IP address „ can physically reach each other without intervening router 223.1.1.1 223.1.1.2 223.1.1.3 223.1.1.4 223.1.2.9 223.1.2.2 223.1.2.1 223.1.3.1 223.1.3.2 223.1.3.27 network consisting of 3 IP networks (for IP addresses starting with 223, first 24 bits are network address) LAN 哈工大计算机学院 李全龙 Network Application Development 1: Introduction 59 IP Addressing How to find the networks? „ Detach each interface from router, host „ create “islands of isolated networks 223.1.1.1 223.1.1.3 223.1.1.4 223.1.2.1 223.1.2.2 223.1.2.6 223.1.3.1 223.1.3.2 223.1.3.27 223.1.1.2 223.1.7.0 223.1.7.1 223.1.8.1 223.1.8.0 223.1.9.1 223.1.9.2 Interconnected system consisting of six networks 哈工大计算机学院 李全龙 Network Application Development 1: Introduction 60 IP Addresses 0network host 10 network host 110 network host 1110 multicast address A B C D class 1.0.0.0 to 127.255.255.255 128.0.0.0 to 191.255.255.255 192.0.0.0 to 223.255.255.255 224.0.0.0 to 239.255.255.255 32 bits given notion of “network”, let’s re-examine IP addresses: “class-full” addressing: E 1111 240.0.0.0 to 255.255.255.255