Decimal and binary conversion
9.2.2 There are several ways to convert decimal numbers to binary numbers. This page will describe one method.
The student may find other methods easier. It is a matter of personal preference.
When converting a decimal number to binary, the biggest power of two that will fit into the decimal number must be determined. If this process is designed to be working with computers, the most logical place to start is with the largest values that will fit into a byte or two bytes. As mentioned earlier, the most common grouping of bits is eight, which make up one byte. However, sometimes the largest value that can be held in one byte is not large enough for the values needed. To accommodate this, bytes are combined. Instead of having two eight-bit numbers, one 16-bit number is created. Instead of three eight-bit numbers, one 24-bit number is created. The same rules apply as they did for eight-bit numbers. Multiply the previous position value by two to get the present column value.
Since working with computers often is referenced by bytes it is easiest to start with byte boundaries and calculate from there. Start by calculating a couple of examples, the first being 6,783. Since this number is greater than 255, the largest value possible in a single byte, two bytes will be used. Start calculating from 215. The binary equivalent of 6,783 is 00011010 01111111.
The second example is 104. Since this number is less than 255, it can be represented by one byte. The binary equivalent of 104 is 01101000.
This method works for any decimal number. Consider the decimal number one million. Since one million is greater than the largest value that can be held in two bytes, 65535, at least three bytes will be needed. By multiplying by two until 24 bits, three bytes, is reached, the value will be 8,388,608. This means that the largest value that 24 bits can hold is 16,777,215. So starting at the 24-bit, follow the process until zero is reached. Continuing with the procedure described, it is determined that the decimal number one million is equal to the binary number 00001111 01000010 01000000.
Figure includes some decimal to binary conversion exercises.
Binary to decimal conversion is just the opposite. Simply place the binary in the table and if there is a one in a column position add that value into the total. Convert 00000100 00011101 to decimal. The answer is 1053.
Figure includes some binary to decimal conversion exercises.
The next page will discuss IPv4 addressing.
Saturday, March 13, 2010
IP addressing
IP addressing
9.2.1 This page will describe IP addressing.
For any two systems to communicate, they must be able to identify and locate each other. The addresses in Figure are not actual network addresses. They represent and show the concept of address grouping.
A computer may be connected to more than one network. In this situation, the system must be given more than one address. Each address will identify the connection of the computer to a different network. Each connection point, or interface, on a device has an address to a network. This will allow other computers to locate the device on that particular network. The combination of the network address and the host address creates a unique address for each device on a network. Each computer in a TCP/IP network must be given a unique identifier, or IP address. This address, which operates at Layer 3, allows one computer to locate another computer on a network. All computers also have a unique physical address, which is known as a MAC address. These are assigned by the manufacturer of the NIC. MAC addresses operate at Layer 2 of the OSI model.
An IP address is a 32-bit sequence of ones and zeros. Figure shows a sample 32-bit number. To make the IP address easier to work with, it is usually written as four decimal numbers separated by periods. For example, an IP address of one computer is 192.168.1.2. Another computer might have the address 128.10.2.1. This is called the dotted decimal format. Each part of the address is called an octet because it is made up of eight binary digits. For example, the IP address 192.168.1.8 would be 11000000.10101000.00000001.00001000 in binary notation. The dotted decimal notation is an easier method to understand than the binary ones and zeros method. This dotted decimal notation also prevents a large number of transposition errors that would result if only the binary numbers were used.
Both the binary and decimal numbers in Figure represent the same values. However, the address is easier to understand in dotted decimal notation. This is one of the common problems associated with binary numbers. The long strings of repeated ones and zeros make errors more likely.
It is easy to see the relationship between the numbers 192.168.1.8 and 192.168.1.9. The binary values 11000000.10101000.00000001.00001000 and 11000000.10101000.00000001.00001001 are not as easy to recognize. It is more difficult to determine that the binary values are consecutive numbers.
The next page will discuss the conversion of binary and decimal numbers.
9.2.1 This page will describe IP addressing.
For any two systems to communicate, they must be able to identify and locate each other. The addresses in Figure are not actual network addresses. They represent and show the concept of address grouping.
A computer may be connected to more than one network. In this situation, the system must be given more than one address. Each address will identify the connection of the computer to a different network. Each connection point, or interface, on a device has an address to a network. This will allow other computers to locate the device on that particular network. The combination of the network address and the host address creates a unique address for each device on a network. Each computer in a TCP/IP network must be given a unique identifier, or IP address. This address, which operates at Layer 3, allows one computer to locate another computer on a network. All computers also have a unique physical address, which is known as a MAC address. These are assigned by the manufacturer of the NIC. MAC addresses operate at Layer 2 of the OSI model.
An IP address is a 32-bit sequence of ones and zeros. Figure shows a sample 32-bit number. To make the IP address easier to work with, it is usually written as four decimal numbers separated by periods. For example, an IP address of one computer is 192.168.1.2. Another computer might have the address 128.10.2.1. This is called the dotted decimal format. Each part of the address is called an octet because it is made up of eight binary digits. For example, the IP address 192.168.1.8 would be 11000000.10101000.00000001.00001000 in binary notation. The dotted decimal notation is an easier method to understand than the binary ones and zeros method. This dotted decimal notation also prevents a large number of transposition errors that would result if only the binary numbers were used.
Both the binary and decimal numbers in Figure represent the same values. However, the address is easier to understand in dotted decimal notation. This is one of the common problems associated with binary numbers. The long strings of repeated ones and zeros make errors more likely.
It is easy to see the relationship between the numbers 192.168.1.8 and 192.168.1.9. The binary values 11000000.10101000.00000001.00001000 and 11000000.10101000.00000001.00001001 are not as easy to recognize. It is more difficult to determine that the binary values are consecutive numbers.
The next page will discuss the conversion of binary and decimal numbers.
Internet architecture
Internet architecture
9.1.7 This page will examine the basic architecture of the Internet.
The Internet enables nearly instantaneous worldwide data communications between anyone, anywhere, at any time.
LANs are networks within limited geographic areas. However, LANs are limited in scale. Although there have been technological advances to improve the speed of communications, such as Metro Optical, Gigabit, and 10-Gigabit Ethernet, distance is still a problem.
Students can focus on the communications between source and destination computers or intermediate computers at the application layer to get an overview of the Internet architecture. Identical instances of an application could be placed on all the computers in a network to ease the delivery of messages. However, this does not scale well. New software would require new applications to be installed on every computer in the network. For new hardware to function properly, the software would need to be modified. Any failure of an intermediate computer or computer application would cause a break in the chain of the messages that are passed.
The Internet uses the principle of network layer interconnection. The goal is to build the functionality of the network in independent modules. This allows a diversity of LAN technologies at Layers 1 and 2 of the OSI model and a diversity of applications at Layers 5, 6, and 7. The OSI model provides a mechanism where the details of the lower and the upper layers are separated. This allows intermediate networking devices to relay traffic without details about the LAN.
This leads to the concept of internetworks, or networks that consist of many networks. A network of networks is called an internetwork, which is indicated with the lowercase i. The network on which the World Wide Web (www) runs is the Internet, which is indicated with a capital I. Internetworks must be scalable with regard to the number of networks and computers attached. They must also be able to handle the transport of data across vast distances. An internetwork must be flexible to account for constant technological innovations. It must be able to adjust to dynamic conditions on the network. And internetworks must be cost-effective. Internetworks must be designed to permit data communications to anyone, anywhere, at any time.
Figure summarizes the connection of one physical network to another through a special purpose computer called a router. These networks are described as directly connected to the router. The router is needed to handle any path decisions required for the two networks to communicate. Many routers are needed to handle large volumes of network traffic.
Figure extends the idea to three physical networks connected by two routers. Routers make complex decisions to allow users on all the networks to communicate with each other. Not all networks are directly connected to one another. The router must have some method to handle this situation.
One option is for a router to keep a list of all computers and all the paths to them. The router would then decide how to forward data packets based on this reference table. Packets would be forwarded based on the IP address of the destination computer. This option would become difficult as more users were added to the network. Scalability is introduced when the router keeps a list of all networks, but leaves the local delivery details to the local physical networks. In this situation, the routers pass messages to other routers. Each router shares information about its connected network.
Figure shows the transparency that users require. However, the physical and logical structures inside the Internet cloud can be extremely complex as shown in Figure . The Internet has grown rapidly to allow more and more users. The fact that the Internet has grown so large, with more than 90,000 core routes and 300,000,000 end users, proves the effectiveness of the Internet architecture.
Two computers located anywhere in the world that follow certain hardware, software, and protocol specifications can communicate reliably. The standardization of ways to move data across networks has made the Internet possible.
This page concludes this lesson. The next lesson will discuss Internet addressing. The first page covers IP addressing.
9.1.7 This page will examine the basic architecture of the Internet.
The Internet enables nearly instantaneous worldwide data communications between anyone, anywhere, at any time.
LANs are networks within limited geographic areas. However, LANs are limited in scale. Although there have been technological advances to improve the speed of communications, such as Metro Optical, Gigabit, and 10-Gigabit Ethernet, distance is still a problem.
Students can focus on the communications between source and destination computers or intermediate computers at the application layer to get an overview of the Internet architecture. Identical instances of an application could be placed on all the computers in a network to ease the delivery of messages. However, this does not scale well. New software would require new applications to be installed on every computer in the network. For new hardware to function properly, the software would need to be modified. Any failure of an intermediate computer or computer application would cause a break in the chain of the messages that are passed.
The Internet uses the principle of network layer interconnection. The goal is to build the functionality of the network in independent modules. This allows a diversity of LAN technologies at Layers 1 and 2 of the OSI model and a diversity of applications at Layers 5, 6, and 7. The OSI model provides a mechanism where the details of the lower and the upper layers are separated. This allows intermediate networking devices to relay traffic without details about the LAN.
This leads to the concept of internetworks, or networks that consist of many networks. A network of networks is called an internetwork, which is indicated with the lowercase i. The network on which the World Wide Web (www) runs is the Internet, which is indicated with a capital I. Internetworks must be scalable with regard to the number of networks and computers attached. They must also be able to handle the transport of data across vast distances. An internetwork must be flexible to account for constant technological innovations. It must be able to adjust to dynamic conditions on the network. And internetworks must be cost-effective. Internetworks must be designed to permit data communications to anyone, anywhere, at any time.
Figure summarizes the connection of one physical network to another through a special purpose computer called a router. These networks are described as directly connected to the router. The router is needed to handle any path decisions required for the two networks to communicate. Many routers are needed to handle large volumes of network traffic.
Figure extends the idea to three physical networks connected by two routers. Routers make complex decisions to allow users on all the networks to communicate with each other. Not all networks are directly connected to one another. The router must have some method to handle this situation.
One option is for a router to keep a list of all computers and all the paths to them. The router would then decide how to forward data packets based on this reference table. Packets would be forwarded based on the IP address of the destination computer. This option would become difficult as more users were added to the network. Scalability is introduced when the router keeps a list of all networks, but leaves the local delivery details to the local physical networks. In this situation, the routers pass messages to other routers. Each router shares information about its connected network.
Figure shows the transparency that users require. However, the physical and logical structures inside the Internet cloud can be extremely complex as shown in Figure . The Internet has grown rapidly to allow more and more users. The fact that the Internet has grown so large, with more than 90,000 core routes and 300,000,000 end users, proves the effectiveness of the Internet architecture.
Two computers located anywhere in the world that follow certain hardware, software, and protocol specifications can communicate reliably. The standardization of ways to move data across networks has made the Internet possible.
This page concludes this lesson. The next lesson will discuss Internet addressing. The first page covers IP addressing.
The OSI model and the TCP/IP model
The OSI model and the TCP/IP model
9.1.6 This page provides a comparison of the OSI model and the TCP/IP model.
The OSI and TCP/IP models have many similarities:
• Both have layers.
• Both have application layers, though they include different services.
• Both have comparable transport and network layers.
• Both use packet-switched instead of circuit-switched technology.
• Networking professionals need to know both models.
Here are some differences of the OSI and TCP/IP models:
• TCP/IP combines the OSI application, presentation, and session layers into its application layer.
• TCP/IP combines the OSI data link and physical layers into its network access layer.
• TCP/IP appears simpler because it has fewer layers.
• When the TCP/IP transport layer uses UDP it does not provide reliable delivery of packets. The transport layer in the OSI model always does.
The Internet was developed based on the standards of the TCP/IP protocols. The TCP/IP model gains credibility because of its protocols. The OSI model is not generally used to build networks. The OSI model is used as a guide to help students understand the communication process.
The Interactive Media Activity will help students understand the differences between the TCP/IP and OSI reference models.
The next page examines the basic architecture of the Internet.
9.1.6 This page provides a comparison of the OSI model and the TCP/IP model.
The OSI and TCP/IP models have many similarities:
• Both have layers.
• Both have application layers, though they include different services.
• Both have comparable transport and network layers.
• Both use packet-switched instead of circuit-switched technology.
• Networking professionals need to know both models.
Here are some differences of the OSI and TCP/IP models:
• TCP/IP combines the OSI application, presentation, and session layers into its application layer.
• TCP/IP combines the OSI data link and physical layers into its network access layer.
• TCP/IP appears simpler because it has fewer layers.
• When the TCP/IP transport layer uses UDP it does not provide reliable delivery of packets. The transport layer in the OSI model always does.
The Internet was developed based on the standards of the TCP/IP protocols. The TCP/IP model gains credibility because of its protocols. The OSI model is not generally used to build networks. The OSI model is used as a guide to help students understand the communication process.
The Interactive Media Activity will help students understand the differences between the TCP/IP and OSI reference models.
The next page examines the basic architecture of the Internet.
Transport layer / Internet layer / Network access layer
Transport layer
9.1.3 This page will explain how the transport layer provides transport services from the source host to the destination host.
The transport layer provides a logical connection between a source host and a destination host. Transport protocols segment and reassemble data sent by upper-layer applications into the same data stream, or logical connection, between end points.
The Internet is often represented by a cloud. The transport layer sends data packets from a source to a destination through the cloud. The primary duty of the transport layer is to provide end-to-end control and reliability as data travels through this cloud. This is accomplished through the use of sliding windows, sequence numbers, and acknowledgments. The transport layer also defines end-to-end connectivity between host applications. Transport layer protocols include TCP and UDP.
The functions of TCP and UDP are as follows:
• Segment upper-layer application data
• Send segments from one end device to another
The functions of TCP are as follows:
• Establish end-to-end operations
• Provide flow control through the use of sliding windows
• Ensure reliability through the use of sequence numbers and acknowledgments
The Interactive Media Activity will help students become familiar with the transport layer protocols.
The next page will describe the Internet layer.
Internet layer
9.1.4 This page explains the functions of the TCP/IP Internet layer.
The purpose of the Internet layer is to select the best path through the network for packets to travel. The main protocol that functions at this layer is IP. Best path determination and packet switching occur at this layer.
The following protocols operate at the TCP/IP Internet layer:
• IP provides connectionless, best-effort delivery routing of packets. IP is not concerned with the content of the packets but looks for a path to the destination.
• Internet Control Message Protocol (ICMP) provides control and messaging capabilities.
• Address Resolution Protocol (ARP) determines the data link layer address, or MAC address, for known IP addresses.
• Reverse Address Resolution Protocol (RARP) determines the IP address for a known MAC address.
IP performs the following operations:
• Defines a packet and an addressing scheme
• Transfers data between the Internet layer and network access layer
• Routes packets to remote hosts
IP is sometimes referred to as an unreliable protocol. This does not mean that IP will not accurately deliver data across a network. IP is unreliable because it does not perform error checking and correction. That function is handled by upper layer protocols from the transport or application layers.
The Interactive Media Activity will help students become familiar with the protocols used in the Internet layer.
The next page will discuss the network access layer.
Network access layer
9.1.5 This page will discuss the TCP/IP network access layer, which is also called the host-to-network layer.
The network access layer allows an IP packet to make a physical link to the network media. It includes the LAN and WAN technology details and all the details contained in the OSI physical and data link layers.
Drivers for software applications, modem cards, and other devices operate at the network access layer. The network access layer defines the procedures used to interface with the network hardware and access the transmission medium. Modem protocol standards such as Serial Line Internet Protocol (SLIP) and Point-to-Point Protocol (PPP) provide network access through a modem connection. Many protocols are required to determine the hardware, software, and transmission-medium specifications at this layer. This can lead to confusion for users. Most of the recognizable protocols operate at the transport and Internet layers of the TCP/IP model.
Network access layer protocols also map IP addresses to physical hardware addresses and encapsulate IP packets into frames. The network access layer defines the physical media connection based on the hardware type and network interface.
Here is an example of a network access layer configuration that involves a Windows system set up with a third party NIC. The NIC would automatically be detected by some versions of Windows and then the proper drivers would be installed. In an older version of Windows, the user would have to specify the network card driver. The card manufacturer supplies these drivers on disks or CD-ROMs.
The Interactive Media Activity will help students become familiar with the network access layer protocols.
The next page explains the similarities and differences between the TCP/IP model and the OSI reference model.
9.1.3 This page will explain how the transport layer provides transport services from the source host to the destination host.
The transport layer provides a logical connection between a source host and a destination host. Transport protocols segment and reassemble data sent by upper-layer applications into the same data stream, or logical connection, between end points.
The Internet is often represented by a cloud. The transport layer sends data packets from a source to a destination through the cloud. The primary duty of the transport layer is to provide end-to-end control and reliability as data travels through this cloud. This is accomplished through the use of sliding windows, sequence numbers, and acknowledgments. The transport layer also defines end-to-end connectivity between host applications. Transport layer protocols include TCP and UDP.
The functions of TCP and UDP are as follows:
• Segment upper-layer application data
• Send segments from one end device to another
The functions of TCP are as follows:
• Establish end-to-end operations
• Provide flow control through the use of sliding windows
• Ensure reliability through the use of sequence numbers and acknowledgments
The Interactive Media Activity will help students become familiar with the transport layer protocols.
The next page will describe the Internet layer.
Internet layer
9.1.4 This page explains the functions of the TCP/IP Internet layer.
The purpose of the Internet layer is to select the best path through the network for packets to travel. The main protocol that functions at this layer is IP. Best path determination and packet switching occur at this layer.
The following protocols operate at the TCP/IP Internet layer:
• IP provides connectionless, best-effort delivery routing of packets. IP is not concerned with the content of the packets but looks for a path to the destination.
• Internet Control Message Protocol (ICMP) provides control and messaging capabilities.
• Address Resolution Protocol (ARP) determines the data link layer address, or MAC address, for known IP addresses.
• Reverse Address Resolution Protocol (RARP) determines the IP address for a known MAC address.
IP performs the following operations:
• Defines a packet and an addressing scheme
• Transfers data between the Internet layer and network access layer
• Routes packets to remote hosts
IP is sometimes referred to as an unreliable protocol. This does not mean that IP will not accurately deliver data across a network. IP is unreliable because it does not perform error checking and correction. That function is handled by upper layer protocols from the transport or application layers.
The Interactive Media Activity will help students become familiar with the protocols used in the Internet layer.
The next page will discuss the network access layer.
Network access layer
9.1.5 This page will discuss the TCP/IP network access layer, which is also called the host-to-network layer.
The network access layer allows an IP packet to make a physical link to the network media. It includes the LAN and WAN technology details and all the details contained in the OSI physical and data link layers.
Drivers for software applications, modem cards, and other devices operate at the network access layer. The network access layer defines the procedures used to interface with the network hardware and access the transmission medium. Modem protocol standards such as Serial Line Internet Protocol (SLIP) and Point-to-Point Protocol (PPP) provide network access through a modem connection. Many protocols are required to determine the hardware, software, and transmission-medium specifications at this layer. This can lead to confusion for users. Most of the recognizable protocols operate at the transport and Internet layers of the TCP/IP model.
Network access layer protocols also map IP addresses to physical hardware addresses and encapsulate IP packets into frames. The network access layer defines the physical media connection based on the hardware type and network interface.
Here is an example of a network access layer configuration that involves a Windows system set up with a third party NIC. The NIC would automatically be detected by some versions of Windows and then the proper drivers would be installed. In an older version of Windows, the user would have to specify the network card driver. The card manufacturer supplies these drivers on disks or CD-ROMs.
The Interactive Media Activity will help students become familiar with the network access layer protocols.
The next page explains the similarities and differences between the TCP/IP model and the OSI reference model.
Friday, February 26, 2010
History and future of TCP/IP / Application layer
History and future of TCP/IP
9.1.1 This page discusses the history and the future of TCP/IP.
The U.S. Department of Defense (DoD) created the TCP/IP reference model because it wanted a network that could survive any conditions. To illustrate further, imagine a world, crossed by multiple cable runs, wires, microwaves, optical fibers, and satellite links. Then imagine a need for data to be transmitted without regard for the condition of any particular node or network. The U.S. DoD required reliable data transmission to any destination on the network under any circumstances. The creation of the TCP/IP model helped to solve this difficult design problem. The TCP/IP model has since become the standard on which the Internet is based.
Think about the layers of the TCP/IP model layers in relation to the original intent of the Internet. This will help reduce confusion. The four layers of the TCP/IP model are the application layer, transport layer, Internet layer, and network access layer. Some of the layers in the TCP/IP model have the same name as layers in the OSI model. It is critical not to confuse the layer functions of the two models because the layers include different functions in each model. The present version of TCP/IP was standardized in September of 1981.
The next page will discuss the application layer of TCP/IP.
Application layer
9.1.2 This page describes the functions of the TCP/IP application layer.
The application layer handles high-level protocols, representation, encoding, and dialog control. The TCP/IP protocol suite combines all application related issues into one layer. It ensures that the data is properly packaged before it is passed on to the next layer. TCP/IP includes Internet and transport layer specifications such as IP and TCP as well as specifications for common applications. TCP/IP has protocols to support file transfer, e-mail, and remote login, in addition to the following:
• File Transfer Protocol (FTP) – FTP is a reliable, connection-oriented service that uses TCP to transfer files between systems that support FTP. It supports bi-directional binary file and ASCII file transfers.
• Trivial File Transfer Protocol (TFTP) – TFTP is a connectionless service that uses the User Datagram Protocol (UDP). TFTP is used on the router to transfer configuration files and Cisco IOS images, and to transfer files between systems that support TFTP. It is useful in some LANs because it operates faster than FTP in a stable environment.
• Network File System (NFS) – NFS is a distributed file system protocol suite developed by Sun Microsystems that allows file access to a remote storage device such as a hard disk across a network.
• Simple Mail Transfer Protocol (SMTP) – SMTP administers the transmission of e-mail over computer networks. It does not provide support for transmission of data other than plain text.
• Telnet – Telnet provides the capability to remotely access another computer. It enables a user to log into an Internet host and execute commands. A Telnet client is referred to as a local host. A Telnet server is referred to as a remote host.
• Simple Network Management Protocol (SNMP) – SNMP is a protocol that provides a way to monitor and control network devices. SNMP is also used to manage configurations, statistics, performance, and security.
• Domain Name System (DNS) – DNS is a system used on the Internet to translate domain names and publicly advertised network nodes into IP addresses.
The next page will discuss the transport layer
9.1.1 This page discusses the history and the future of TCP/IP.
The U.S. Department of Defense (DoD) created the TCP/IP reference model because it wanted a network that could survive any conditions. To illustrate further, imagine a world, crossed by multiple cable runs, wires, microwaves, optical fibers, and satellite links. Then imagine a need for data to be transmitted without regard for the condition of any particular node or network. The U.S. DoD required reliable data transmission to any destination on the network under any circumstances. The creation of the TCP/IP model helped to solve this difficult design problem. The TCP/IP model has since become the standard on which the Internet is based.
Think about the layers of the TCP/IP model layers in relation to the original intent of the Internet. This will help reduce confusion. The four layers of the TCP/IP model are the application layer, transport layer, Internet layer, and network access layer. Some of the layers in the TCP/IP model have the same name as layers in the OSI model. It is critical not to confuse the layer functions of the two models because the layers include different functions in each model. The present version of TCP/IP was standardized in September of 1981.
The next page will discuss the application layer of TCP/IP.
9.1.2 This page describes the functions of the TCP/IP application layer.
The application layer handles high-level protocols, representation, encoding, and dialog control. The TCP/IP protocol suite combines all application related issues into one layer. It ensures that the data is properly packaged before it is passed on to the next layer. TCP/IP includes Internet and transport layer specifications such as IP and TCP as well as specifications for common applications. TCP/IP has protocols to support file transfer, e-mail, and remote login, in addition to the following:
• File Transfer Protocol (FTP) – FTP is a reliable, connection-oriented service that uses TCP to transfer files between systems that support FTP. It supports bi-directional binary file and ASCII file transfers.
• Trivial File Transfer Protocol (TFTP) – TFTP is a connectionless service that uses the User Datagram Protocol (UDP). TFTP is used on the router to transfer configuration files and Cisco IOS images, and to transfer files between systems that support TFTP. It is useful in some LANs because it operates faster than FTP in a stable environment.
• Network File System (NFS) – NFS is a distributed file system protocol suite developed by Sun Microsystems that allows file access to a remote storage device such as a hard disk across a network.
• Simple Mail Transfer Protocol (SMTP) – SMTP administers the transmission of e-mail over computer networks. It does not provide support for transmission of data other than plain text.
• Telnet – Telnet provides the capability to remotely access another computer. It enables a user to log into an Internet host and execute commands. A Telnet client is referred to as a local host. A Telnet server is referred to as a remote host.
• Simple Network Management Protocol (SNMP) – SNMP is a protocol that provides a way to monitor and control network devices. SNMP is also used to manage configurations, statistics, performance, and security.
• Domain Name System (DNS) – DNS is a system used on the Internet to translate domain names and publicly advertised network nodes into IP addresses.
The next page will discuss the transport layer
Module 9: TCP/IP Protocol Suite and IP Addressing Overview
Overview
The Internet was developed to provide a communication network that could function in wartime. Although the Internet has evolved from the original plan, it is still based on the TCP/IP protocol suite. The design of TCP/IP is ideal for the decentralized and robust Internet. Many common protocols were designed based on the four-layer TCP/IP model.
It is useful to know both the TCP/IP and OSI network models. Each model uses its own structure to explain how a network works. However, there is much overlap between the two models. A system administrator should be familiar with both models to understand how a network functions.
Any device on the Internet that wants to communicate with other Internet devices must have a unique identifier. The identifier is known as the IP address because routers use a Layer 3 protocol called the IP protocol to find the best route to that device. The current version of IP is IPv4. This was designed before there was a large demand for addresses. Explosive growth of the Internet has threatened to deplete the supply of IP addresses. Subnets, Network Address Translation (NAT), and private addresses are used to extend the supply of IP addresses. IPv6 improves on IPv4 and provides a much larger address space. Administrators can use IPv6 to integrate or eliminate the methods used to work with IPv4.
In addition to the physical MAC address, each computer needs a unique IP address to be part of the Internet. This is also called the logical address. There are several ways to assign an IP address to a device. Some devices always have a static address. Others have a temporary address assigned to them each time they connect to the network. When a dynamically assigned IP address is needed, a device can obtain it several ways.
For efficient routing to occur between devices, issues such as duplicate IP addresses must be resolved.
This module covers some of the objectives for the CCNA 640-801, INTRO 640-821, and ICND 640-811 exams.
Students who complete this module should be able to perform the following tasks:
• Explain why the Internet was developed and how TCP/IP fits the design of the Internet
• List the four layers of the TCP/IP model
• Describe the functions of each layer of the TCP/IP model
• Compare the OSI model and the TCP/IP model
• Describe the function and structure of IP addresses
• Understand why subnetting is necessary
• Explain the difference between public and private addressing
• Understand the function of reserved IP addresses
• Explain the use of static and dynamic addressing for a device
• Understand how dynamic addresses can be assigned with RARP, BootP, and DHCP
• Use ARP to obtain the MAC address to send a packet to another device
• Understand the issues related to addressing between networks
The Internet was developed to provide a communication network that could function in wartime. Although the Internet has evolved from the original plan, it is still based on the TCP/IP protocol suite. The design of TCP/IP is ideal for the decentralized and robust Internet. Many common protocols were designed based on the four-layer TCP/IP model.
It is useful to know both the TCP/IP and OSI network models. Each model uses its own structure to explain how a network works. However, there is much overlap between the two models. A system administrator should be familiar with both models to understand how a network functions.
Any device on the Internet that wants to communicate with other Internet devices must have a unique identifier. The identifier is known as the IP address because routers use a Layer 3 protocol called the IP protocol to find the best route to that device. The current version of IP is IPv4. This was designed before there was a large demand for addresses. Explosive growth of the Internet has threatened to deplete the supply of IP addresses. Subnets, Network Address Translation (NAT), and private addresses are used to extend the supply of IP addresses. IPv6 improves on IPv4 and provides a much larger address space. Administrators can use IPv6 to integrate or eliminate the methods used to work with IPv4.
In addition to the physical MAC address, each computer needs a unique IP address to be part of the Internet. This is also called the logical address. There are several ways to assign an IP address to a device. Some devices always have a static address. Others have a temporary address assigned to them each time they connect to the network. When a dynamically assigned IP address is needed, a device can obtain it several ways.
For efficient routing to occur between devices, issues such as duplicate IP addresses must be resolved.
This module covers some of the objectives for the CCNA 640-801, INTRO 640-821, and ICND 640-811 exams.
Students who complete this module should be able to perform the following tasks:
• Explain why the Internet was developed and how TCP/IP fits the design of the Internet
• List the four layers of the TCP/IP model
• Describe the functions of each layer of the TCP/IP model
• Compare the OSI model and the TCP/IP model
• Describe the function and structure of IP addresses
• Understand why subnetting is necessary
• Explain the difference between public and private addressing
• Understand the function of reserved IP addresses
• Explain the use of static and dynamic addressing for a device
• Understand how dynamic addresses can be assigned with RARP, BootP, and DHCP
• Use ARP to obtain the MAC address to send a packet to another device
• Understand the issues related to addressing between networks
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