Chapter 11 Configuring and Testing Your Network

This chapter studies the process for connecting and configuring computer, switch, and routers into an Ethernet LAN. This will introduce also the basic configuration for Cisco network devices and is require the use of the Cisco Internetwork Operating System (IOS) and the related configuration files for intermediary devices. It is used for routers, LAN switches, small Wireless Access Points, large routers with dozens of interfaces, and many other devices. The services provided by the Cisco IOS are generally accessed using a command line interface (CLI).

The Cisco IOS is designed as a modal operating system. The term modal describes a system where there are different modes of operation, each having its own domain of operation. The CLI uses a hierarchical structure for the modes. The major modes are: User executive mode, Privileged executive mode, Global configuration mode, other specific configuration modes. Each mode is used to accomplish particular tasks and has a specific set of commands that are available when in that mode. The two primary modes of operation are: User EXEC, Privileged EXEC. The user EXEC mode is at the top of the modal hierarchical structure. This mode is the first entrance into the CLI of an IOS router. The privileged EXEC mode can be identified by the prompt ending with the # symbol.

Switch#

In order to access the privileged EXEC mode, use the enable command. The privileged EXEC mode is sometimes called the enable mode.

The syntax for entering the enable command is:

Router>enable

Configuring Router Ethernet Interfaces

Router Ethernet interfaces are used as the gateways for the end devices on the LANs directly connected to the router.

Each Ethernet interface must have an IP address and subnet mask to route IP packets.

To configure an Ethernet interface follow these steps:

1. Enter global configuration mode.

2. Enter interface configuration mode.

3. Specify the interface address and subnet mask.

4. Enable the interface.

Configuring Router Serial Interfaces

Serial interfaces are used to connect WANs to routers at a remote site or ISP.

To configure a serial interface follow these steps:

1. Enter global configuration mode.

2. Enter interface mode.

3. Specify the interface address and subnet mask.

4. Set the clock rate if a DCE cable is connected. Skip this step if a DTE cable is connected.

5. Turn on the interface.

Chapter 10 Planning and Cabling Networks

In this chapter, we will examine various media and the distinct roles they play with the devices that they connect. You will identify the cables needed to make successful LAN and WAN connections and learn how to use device management connections.

COMS113-Data Communication and Networks

Chapter 9 ETHERNET

Ethernet is the leading LAN technology in use today. Ethernet can be related but it is actually implemented in the lower half of the Data Link layer, which is known as the Media Access Control (MAC) sub layer, and the Physical layer only. The success of Ethernet is due to the following factors:

·         Simplicity and ease of maintenance

·         Ability to incorporate new technologies

·         Reliability

·         Low cost of installation and upgrade

Ethernet shared media and collision detection techniques were adapted from ALOHANET radio network. Ethernet was designed to accommodate multiple computers that were interconnected on a shared bus topology. All Ethernet nodes share the media to receive the data sent to it, each node needs a unique address. IP addresses use to communicate between networks while MAC address used within networks across the local media. In Ethernet, different MAC addresses are used for Layer 2 unicast, multicast, and broadcast communications. A unicast MAC address is the unique address used when a frame is sent from a single transmitting device to single destination device. Unicast  IP and MAC destination address are used by the source to forward a packet. With a broadcast, the packet contains a destination IP address that has all ones (1s) in the host portion. Broadcast IP and MAC destination addresses are used by the source to forward a packet to all hosts on the network. Recall that multicast addresses allow a source device to send a packet to a group of devices. Devices that belong to a multicast group are assigned a multicast group IP address. Multicast IP and MAC destination addresses deliver packet/frame to specific group of member hosts.

In the last few years, switches have quickly become a fundamental part of most networks. Switches allow the segmentation of the LAN into separate collision domains. Switch acting as a bridge between two shared media hubs. Two collision domains, one for each media LAN. Switch at the center of the LAN, each computer has its own collision domain.

Logical Link Control (LLC)

Handles the communication between the upper layers and the lower layers, typically hardware. Implemented in software and is independent of the physical equipment; can be considered as the NIC driver software in a PC. Provides sub addressing to identify the network protocol that uses the link layer service. Destination Service Access Point (DSAP) and the Source Service Access Point (SSAP): identifies a protocol, or set of protocols, in the next higher OSI layer, the Network layer.

The two Datalink sublayers are as follows:

Logical Link Control (LLC)

Handles the communication between the upper layers and the lower layers, typically hardware. Implemented in software and is independent of the physical equipment; can be considered as the NIC driver software in a PC. Provides sub addressing to identify the network protocol that uses the link layer service. Destination Service Access Point (DSAP) and the Source Service Access Point (SSAP): identifies a protocol, or set of protocols, in the next higher OSI layer, the Network layer.

Media Access Control (MAC)

Ethernet MAC sublayer has the following responsibilities: Data Encapsulation: Fame assembly before transmission, and frame parsing/error detection during and after reception. Media Access Control: Controls frames on and off the media, including initiation of frame transmission and recovery from transmission failure. Addressing: Provides physical address (MAC address) that enables frames to be delivered to destination hosts. Media Access Control is implemented by hardware, typically in the host NIC or equivalent.

COMS 113-Data Communications

Chapter 8- OSI Layer

This chapter introduces the overall functions of the Physical layer in addition with the standards and protocols that manage the transmission of data across the local media. The role of the OSI Physical layer is to encode the binary digits that represent Data Link layer frames into signals and to transmit and receive these signals across the physical media - copper wires, optical fiber, and wireless - that connect network devices. It has a job also to retrieve these individual signals from the media, restore them to their bit representations, and pass the bits up to the Data Link layer as a complete frame. The three basic forms of network media in which data is represented are copper cable, fiber, and wireless. The representation of the bits - that is, the type of signal - depends on the type of media. For copper cable media, the signals are patterns of electrical pulses. For fiber, the signals are patterns of light. For wireless media, the signals are patterns of radio transmissions.

The three fundamental functions of physical layer are as follows: the physical components, data encoding, and signaling. The physical components are the electronic hardware devices, media and connectors that transmit and carry the signals to represent the bits.

Encoding is a method of converting a stream of data bits into a predefined code. Using predictable patterns helps to distinguish data bits from control bits and provide better media error detection. In addition to creating codes for data, encoding methods at the Physical layer may also provide codes for control purposes such as identifying the beginning and end of a frame. The transmitting host will transmit the specific pattern of bits or a code to identify the beginning and end of the frame.

            In Signaling the Physical layer must generate the electrical, optical, or wireless signals that represent the "1" and "0" on the media. Signaling methods represents the bits.  The Physical layer standards must define what type of signal represents a "1" and a "0".

Data transfer can be measured in three ways such as:  Bandwidth, Throughput, and Goodput. Bandwidth of the media is the capacity of the medium to carry data and is typically measured in kilobits per second (kbps) or megabits per second (Mbps). Throughput is the measure of the transfer of bits across the media over a given period of time. Goodput is the measure of usable data transferred over a given period of time, and is therefore the measure that is of most interest to network users.Advantages using code groups include:

·         Reducing bit level error

·         Limiting the effective energy transmitted into the media

·         Helping to distinguish data bits from control bits

·         Better media error detection

What have I learned in IT19...

As I enrolled IT 19(Technical Presentation Skills in IT), it needs an extra effort for completion and I also experience a little difficulties. At first, we have an activities during our laboratory, an on-the-spot group activity that enhances and develops more our self confidence. IT 19 subject is just making up  or constructing a presentation..Few meetings we were discussed the guidelines and tips in constructing a presentation.And later on we are required to submit any interesting topics to be approve by our instructor.The approved topic will be presented in the class.As we made our presentation there are so many guidelines or tips we need to follow.It's just about making a simple PowerPoint presentation but a presentable presentation. We should "KEEP IT SIMPLE and SHORT. We can also post all the things we want in our presentation in order to fulfill but we  should follow the guidelines and tips to achieve a good presentation. We must be focus with our viewers, be sure that it can easily be understood, and it should have a good use animation. We also observe the presentations font size, and must assure that the people or the audience can read it clear.This project also enhances and develops our self confidence. Because as we presented the presentation we should assure that the audience will  well-understand and informed.

 As we go on, we learned more. We were given some tasks and assignments that were not easy to do. We have given an infomercial project, wherein we need to endorse a particular degree program.We produce a video about such program, introduce its importance in the society, the benefits that students could get upon enrolling the program, and the opportunities waiting in the post graduation. It is just like an advertisement. As we made the project, we encountered the U lead installer which is new to us because that was never introduced in other subjects. We also tried the Movie Maker but it does not exist because wet found out that U Lead is better than Movie Maker. This installer serves as the key that widens our imagination and thinking, it also enhances our creativity. Those two advantageous factors we used resulted to the production of a nice  output an advertisement.The project enhances and develops again our self-confidence .We also learned about Multimedia and etc..

We also produce a documentary film. We mingled and interviewed different persons in different levels, we also visit to places we didn't used to go for documentation purposes.We do bonding with our co-groups.It is  just a documentary film but the scenes in our video used to be edited in order to portray more the message we want to convey and understand by the audience. It was a hard task but with cooperation of our co-group, we did it.

Taking up this course is my great privileged  because it really broadens my understanding about IT presentation or Technical Presentations. It also develops, enhances,  and practice my skills in technical  aspects. Even if I have experienced difficulties upon taking it, but the learning and knowledge I've gain is enough to repay it. I won't also forget those experience which has the great contribution or molding my personality and characteristics, like the building or self-esteem, creativeness, self-confidence and hard work. I also learned the essence of teamwork. If each members of the group would help, cooperate, and share his/her ideas a difficult activity can be a simple one.

IT19 is a challenge.Once you take up this subject, just go with the flow. Don't be afraid to try, exploration is where you can learn many things. Just sit down, let yourself learn, give your best, and enjoy then you'll see how it is feels great having completed not just this course, IT19, but with others.