3/9/2021 Network+ Guide to Networks Objectives (1 of 2) Objectives (2 of 2) Eighth Edition 3.1 Find the MAC address of a computer and explain its function 3.4 Describe domain names and the name resolution process in network communications Chapter 3 3.5 Use command-line tools to troubleshoot problems with 3.2 Configure TCP/IP settings on a computer, including IP address, network addresses Addressing on Networks subnet mask, default gateway, and DNS servers 3.3 Explain the purpose of ports and sockets, and identify the ports of several common, network protocols © 2019 Cengage. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for © 2019 Cengage. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license © 2019 Cengage. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license classroom use. 1 distributed with a certain product or service or otherwise on a password-protected website for classroom use. distributed with a certain product or service or otherwise on a password-protected website for classroom use. 1 3/9/2021 Addressing Overview MAC Addresses IP Addresses (1 of 2) • Four addressing methods: • Traditional MAC addresses contain two parts: • Static IP addresses are assigned manually by the network administrator • Data Link layer MAC address • First 24 bits are known as the OUI (Organizationally Unique Identifier) or • Dynamic IP addresses are automatically assigned by a DHCP (Dynamic Host - 48 bits, written as six hex numbers separated by colons manufacturer-ID Configuration Protocol) server - - Also called physical address Assigned by the IEEE • You’ll learn more about DHCP later in the chapter • Network layer IP address • Last 24 bits make up the extension identifier or device ID • To view TCP/IP settings on a Windows 10 computer: - Manufacturers assign each NIC a unique device ID - IPv4 addresses have 32 bits and are written as four decimal numbers called octets • In Control Panel, open the Network and Sharing Center. Click Change adapter settings - IPv6 addresses have 128 bits and are written as eight blocks of hexadecimal number • Brief explanation of settings: • Transport layer port numbers • Gateway—Device that nodes use for access to the outside world • Application layer FQDNs, computer names, and host names • Subnet mask—Used to indicate what portion of an IP address is the network portion - Fully qualified domain name (FQDN)—A unique character-based name (network ID) and what part is the host portion (host ID) • DNS server—Server responsible for tracking computer names and their IP addresses © 2019 Cengage. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license © 2019 Cengage. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license © 2019 Cengage. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use. 4 distributed with a certain product or service or otherwise on a password-protected website for classroom use. 5 distributed with a certain product or service or otherwise on a password-protected website for classroom use. 6 2 3/9/2021 IP Addresses (2 of 2) IPv4 Addresses (1 of 7) IPv4 Addresses (2 of 7) – The OLD Way • You can use the ipconfig utility in a Command Prompt to find out current TCP/IP • IPv4 addresses • Classful addressing settings • 32-bit address • The dividing line between the network and host portions is determined by the • IP address, subnet mask, gateway - Usually written as four groups of 8 bits each (known as octets), using base-10 notation numerical range the IP address falls in • Example of an IPv4 address: 72.56.105.12 • Classful IPv4 addresses are divided into five classes: • Two types of IP addresses: • Each of the four octets can be any number from 0 to 255 • Class A, Class B, Class C, Class D, and Class E • IPv4—A 32-bit address • Some IP addresses are reserved • Classes A, B, and C licensed IP addresses are available for use on the Internet • IPv6—A 128-bit address – Not used at Bloomsburg • Called public IP addresses • Originally: IPv4 addresses were divided into classes based on the octets • A company can use private IP addresses on its private networks • ipconfig /all • Currently: IPv4 addresses are managed as single 32-bit "bitstrings" • IEEE recommends the following IP addresses be used for private networks: • Shows all information about network connections • Divided into Network ID and Host ID, at any desired bit position • 10.0.0.0 through 10.255.255.255 • Includes MAC address, gateway, DHCP server, DNS server • 172.16.0.0 through 172.31.255.255 • 192.168.0.0 through 192.168.255.255 © 2019 Cengage. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license © 2019 Cengage. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license © 2019 Cengage. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use. 7 distributed with a certain product or service or otherwise on a password-protected website for classroom use. 8 distributed with a certain product or service or otherwise on a password-protected website for classroom use. 9 3 3/9/2021 IPv4 Addresses (3 of 7) IPv4 Addresses (4 of 7) IPv4 Addresses (5 of 7) • Table 3-1 IP address classes • Classes D and E addresses were not available for general use: • Network Address Translation (NAT)—A technique designed to conserve • Class D begin with octets 224–239 and are used for multicasting public IP addresses needed by a network Class Network octets* Approximate Approximate number • Class E begin with octets 240–254 and are used for research • Address translation—Process where a gateway device substitutes the private number of possible of IP addresses in each IP addresses with its own public address networks network • Table 3-2 Reserved IP addresses A 1.x.y.z to 126.x.y.z 126 16 million • When these computers need access to other networks or Internet IP address(es) Function B 128.0.x.y to 191.255.x.y 16,000 65,000 • Port Address Translation (PAT)—Process of assigning a TCP port number to 255.255.255.255 Used for broadcast messages by TCP/IP background processes. A each ongoing session between a local host and Internet host C 192.0.0.x to 223.255.255.x 2 million 254 broadcast message is read by every node on the network. 0.0.0.0 Currently unassigned 127.0.0.1 through Used for research or can indicate your own computer, in which case 127.255.255.254 it is called the loopback address. 169.254.0.1 through Used to create an APIPA (Automatic Private IP Addressing) address 169.254.255.254 when a computer configured for DHCP first connects to the network and is unable to lease an IPv4 address from the DHCP server. © 2019 Cengage. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license © 2019 Cengage. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license © 2019 Cengage. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use. 10 distributed with a certain product or service or otherwise on a password-protected website for classroom use. 11 distributed with a certain product or service or otherwise on a password-protected website for classroom use. 12 4 3/9/2021 IPv4 Addresses (6 of 7) IPv4 Addresses (7 of 7) IPv4 Addresses – The New Way • Two variations of NAT to be aware of: • CIDR – Classless Internet Domain Routing • SNAT (Static (or Source) Network Address Translation)—The gateway assigns the same • Separate "mask" (a.k.a. netmask or subnet mask) indicates which bits are public IP address to a host each time it makes a request to access the Internet Network ID (remainder will be Host ID bits) • DNAT (Dynamic Network Address Translation)—The gateway has a pool of public • Classes A, B, and C each correspond to a netmask: address that it is free to assign to a local host when it makes a request to access the Internet - Class A – "/8", or "255.0.0.0" (binary: 11111111 00000000 00000000 00000000) - Class B – "/16", or "255.255.0.0" (11111111 11111111 00000000 00000000) - Class C – "/24", or "255.255.255.0" (11111111 11111111 11111111 00000000) • Private-use networks, in CIDR notation: • 10.0.0.0 / 8 • 172.16.0.0 / 12 – Network ID portion is 1½ octets • 192.168.0.0 / 16 © 2019 Cengage.