© 2007 Cisco Systems, Inc. All rights reserved. Module 15 Advanced Networks 15.0 Introduction   This chapter focuses on advanced networking topics, including network design, network component upgrades, and e-mail server installations. Basic networking topics such as safety, network components, and preventive maintenance are also discussed. To meet the expectations and needs of your customers and network users, you must be familiar with networking technologies. You must understand the basics of how a network is designed and why some components affect the flow of data on a network. Troubleshooting advanced network situations is also described in this chapter. After completing this chapter, you will meet these objectives: list of 8 items • Identify potential safety hazards and implement proper safety procedures related to networks. • Design a network based on the customer's needs. • Determine the components for your customer's network. • Implement the customer's network. • Upgrade the customer's network. • Describe installation, configuration, and management of a simple mail server. • Describe preventive maintenance procedures for networks. • Troubleshoot the network. 15.1 Identify potential safety hazards and implement proper safety procedures related to networks  Installing network cables, whether copper or fiber optic, can be dangerous. Often, cables must be pulled through ceilings and walls where there are obstacles and unexpected or toxic materials. You should wear clothing that protects you from these materials. For example, wear long pants, long-sleeved shirts, sturdy shoes that cover your feet, and gloves. Most importantly, wear safety glasses. If possible, ask building management, or someone responsible for the building, if there are any dangerous materials or obstacles that you need to be aware of before entering the ceiling area. Be aware of the safety issues when using a ladder: list of 5 items • Read the labels on the ladder and follow any safety instructions written on it. • Never stand on the top rung of the ladder. You could easily lose your balance and fall. • Make sure that people in the area know you will be working there. • Cordon off the area with caution tape or safety cones. • When you are using a ladder that leans up against a wall, follow the instructions written on the ladder, and have someone hold the ladder for you to help keep the ladder steady. list end The tools required to install copper and fiber-optic cable may be dangerous to use. Rules should always be followed when working with cables: list of 4 items • Make sure that the tools you are using are in good working order. • Watch what you are doing and take your time. Make sure that you do not cut yourself or place anyone in danger. • Always wear safety glasses when cutting, stripping, or splicing cables of any kind. Tiny fragments can injure your eyes. • Wear gloves whenever possible and make sure to dispose of any waste properly. list end Use common sense when you take care of any problems. Call another person to help you if you need help. After completing this section, you will meet these objectives: list of 2 items • Explain fiber-optic safety. • Explain cable, cable cutters, and cable cutting safety hazards.  15.1   Identify potential safety hazards and implement proper safety procedures related to networks       15.1.1   Explain fiber-optic safety     table end Fiber optics are useful for communications, but they have certain hazards: list of 3 items • Dangerous chemicals • Light that you cannot see that can burn your eyes • Tools with sharp edges that produce glass splinters list end Specific types of tools and chemicals are used when working with fiber-optic cable. These materials must be handled safely. Chemicals The solvents and glues used with fiber optics are dangerous. You should handle them with extreme care. Read any instructions and follow them carefully. Also, read the MSDS that accompanies the chemicals to know how to treat someone in an emergency. Tools When working with any tool, safety should always be your first priority. Any compromise in safety could result in serious injury or even death. The tools used for working with fiber optics have sharp cutting surfaces that are used to scribe glass. Other tools pinch cables with high pressure to fasten connectors to them. These tools can produce shards of glass that can splinter and fly into the air. You must avoid getting them in your skin, mouth, or eyes. Harmful Light Protect your eyes from the harmful light that may be in the fiber-optic strands. The light is a color that humans cannot see. It can damage your eyes before you can feel it. When you use a magnifier to inspect fiber-optic cable and connectors, the light emitted from the fiber could be directed into your eye. When working with fiber, be sure to disconnect the light source. Special detectors can tell you if a fiber is energized. Glass Shards The process of cutting and trimming the strands of fiber-optic cables can produce tiny fragments of glass or plastic that can penetrate your eyes or skin and cause severe irritation. The fibers can be extremely difficult to see on your skin because they are clear and small. When working with fiber-optic cabling, the working surface should be a dark mat so that tiny glass or plastic fragments can be seen. The mat should also be resistant to chemical spills. You should keep the work area clean and neat. Never pick up fiber-optic fragments with your fingers. Use tape to pick up small fragments and dispose of them properly. Use a disposable container, such as a plastic bottle with a screw-on lid, to store fiber fragments. Close the lid tightly before disposing of the container. CAUTION: Obtain proper training before you attempt to cut, strip, or splice fiber-optic cable. An experienced technician should supervise you until you become adequately skilled.  15.1   Identify potential safety hazards and implement proper safety procedures related to networks       15.1.2   Explain cable, cable cutters, and cable cutting safety hazards     table end All levels of technicians should know the hazards before working with network cable and equipment. CAUTION: When handling cable, always wear eye protection. Never touch the ends of any type of cable with bare skin. Copper Cable Hazards Copper cables can also be dangerous to handle. When you cut copper cable, the small copper strands can puncture your skin or cut you. The small pieces that come off after cutting cables often fly into the air. Remember to always wear safety glasses when cutting any type of cable. The cutting and crimping tools used to repair or terminate copper cables can be dangerous if not used properly. Read the documentation that comes with the tool. Practice using the tool on scrap cable, and ask an experienced installer for help if you need it. Remember that copper cable conducts electricity. An equipment fault, static electricity, or lightning can energize even a disconnected cable. If in doubt, test the cable you are working on with a simple voltage detector before touching it. 15.2 Design a network based on the customer's needs  A network works best if it is designed to meet the needs of the customer. Building a network requires analysis of the environment and an understanding of networking options. You should interview the customer, as well as any other people involved in the project. It is important to have a general idea about the hardware and software that will be used on the network. You should inquire about future growth of the company and the network. After completing this section, you will meet these objectives: list of 2 items • Determine a topology. • Determine protocols and network applications.  15.2   Design a network based on the customer's needs       15.2.1   Determine a topology    table end Understanding the needs of the customer and determining the general layout of the new network are required to properly determine the network topology. These important issues need to be discussed with the customer: list of 3 items • Cable and wireless types • Expandability • Number and location of users list end The number of users and the estimated amount of future growth determines the initial physical and logical topology of the network. You should create a checklist to record the needs of your customer. An inspection, called a site survey, should be done early in the project. A site survey is a physical inspection of the building that helps determine a basic logical topology, which is the flow of data and protocols. The number of users and the estimated amount of future growth determines the initial physical and logical topology of the network. You should consider the following factors: list of 3 items • Where the users' end-station computers will be. • Where to position network equipment such as switches and routers. • Where the servers will be positioned. This may be in the same room as the network equipment, or it could be elsewhere. The decision is often based on available space, power, security, and air conditioning. list end A floor plan or blueprint is helpful to determine the physical layout of equipment and cables. Figure 1 shows a comparison of network topologies. If a floor plan or blueprint is not available, you should make a drawing of where the network devices will be located, including the location of the server room, the printers, the end stations, and cable runs. This drawing can be used for discussions when the customer makes the final layout decisions. Types of Network Topologies Bus Topology Ring Topology Star Topology Extended Star Topology Hierarchical Topology Mesh Topology  15.2   Design a network based on the customer's needs       15.2.2   Determine protocols and network applications    table end In the design of a network, you must determine the protocols that are going to be used. Some protocols are proprietary and only work on specific equipment, while other protocols are open standards and work on a variety of equipment. Figure 1 shows details of the various network protocols. Consider the following when selecting protocols: list of 4 items • The TCP/IP suite of protocols is required for every device to connect to the Internet. This makes it a preferred protocol for networking. • NetBEUI is a small, fast protocol that is useful in low security networks. NetBEUI performs well in a small network that is not connected to the Internet. It is easy to install and requires no configuration. However, NetBEUI can cause unnecessary traffic on a large network, so it is not a good choice if there will be network growth. • IPX/SPX is a protocol that belongs to older versions of Novell Netware. Because of the growth of the Internet, newer versions of Novell Netware use TCP/IP instead of IPX/SPX. • Apple Macintosh networks have abandoned the AppleTalk protocol for the TCP/IP suite of protocols to ensure connectivity with other TCP/IP networks, most notably the Internet. list end When the TCP/IP protocol stack is enabled, other protocols become available on specific ports, as shown in Figure 2.   Worksheet Protocols Identify the proper protocol to use in different network configurations 15.3 Determine the components for your customer's network   The choice of network topology determines the type of devices, cables, and network interfaces that will be required to construct the network. In addition, an outside connection to an Internet service provider must be set up. One of the steps in building a network is to determine suitable network components that work with user devices and the cabling of the network. After completing this section, you will meet these objectives: list of 4 items • Select cable types. • Select ISP connection types. • Select network cards. • Select the network device.  15.3   Determine the components for your customer's network        15.3.1   Select cable types    table end Select the cable type that is the most beneficial and cost effective for the users and services that will connect to the network. Cable Types The size of the network determines the type of network cable that will be used. Most networks today are wired using one or more kinds of types of twisted-pair copper cable: list of 4 items • Cat5 • Cat5e • Cat6 • Cat6A list end Cat5 and Cat5e cables look the same, but Cat 5e cable is manufactured with a higher standard to allow for higher data transfer rates. Cat6 cable is constructed with even higher standards than Cat5e. Cat6 cable may have a center divider to separate the pairs inside the cable. The most common type of cable used in a network is Cat5e. Cat5e is suitable for Fast Ethernet up to 330 feet (100 m). Some businesses and homes have installed Cat6 cable so that they are prepared for additional bandwidth requirements in the future. Applications such as video, videoconferencing, and gaming use a large amount of bandwidth. The most recent type of twisted-pair cable available is Cat6A. Cat6A cable carries Ethernet signals at a rate of 10 Gbps. The abbreviation for 10 Gb Ethernet over twisted-pair cable is 10GBase-T, as defined in the IEEE 802.3an-2006 standard. Customers who need high bandwidth networks can benefit from installing cable that can support Gigabit Ethernet or 10 Gb Ethernet. New or renovated office buildings often have some type of UTP cabling that connects every office to a central point called the Main Distribution Facility (MDF). The distance limitation of UTP cabling used for data is 330 feet (100 m). Network devices that are farther than this distance limitation need a repeater or hub to extend the connection to the MDF. Cost When designing a network, cost is a consideration. Installing cables is expensive, but after a one-time expense, a wired network is normally inexpensive to maintain. Most of the devices on a wired network cost much less than the devices on a wireless network. Security A wired network is usually more secure than a wireless network. The cables in a wired network are usually installed in walls and ceilings, and therefore not easily accessible. Wireless is easier to eavesdrop. The signals are available to anyone who has a receiver. To make a wireless network as secure as a wired network requires the use of encryption. Design for the Future Many organizations install the highest grade cable available to ensure that their networks can handle the network speeds that will be available in the future. The organizations want to avoid having to do expensive reinstalling of cable later. You and your customer must decide if the cost of installing a higher grade cable is necessary. Wireless A wireless solution may be possible in places where cables cannot be installed. Consider an older, historic building where local building codes do not permit structural modifications. In this case, installing cable is not possible and therefore a wireless connection is the only solution. Twisted Pair Cable Cat 5e cable is an enhanced version of Cat 5 that adds specifications for far end crosstalk. It was formally defined in 2001 in the TIA/EIA-568-B standard, which no longer recognizes the original Cat 5 specification. Cat-6 features more stringent specifications for crosstalk and system noise. The cable standard is suitable for 10BASE-T / 100BASE-TX and1000BASE- T(Gigabit Ethernet) connections. It provides performance of up to 250 MHz.  15.3   Determine the components for your customer's network        15.3.2   Select ISP connection type    table end The ISP (Internet service provider) that you choose can have a noticeable effect on network service. Some private resellers that connect to a phone company may sell more connections than allowed, which slows the overall speed of the service to customers. There are three main considerations for an Internet connection: list of 3 items • Speed • Reliability • Availability list end POTS A plain old telephone system (POTS) connection is extremely slow but it is available wherever there is a telephone. The modem uses the telephone line to transmit and receive data. ISDN The Integrated Services Digital Network (ISDN) offers faster connection times and has faster speeds than dial-up, and allows multiple devices to share a single telephone line. ISDN is very reliable because it uses POTS lines. ISDN is available in most places where the telephone company supports digital signaling. DSL Digital Subscriber Line (DSL), like ISDN, allows multiple devices to share a single telephone line. DSL speeds are generally higher than ISDN. DSL allows the use of high-bandwidth applications or multiple users to share the same connection to the Internet. In most cases, the copper wires already in your home or business are capable of carrying the signals needed for DSL communication. There are limitations to DSL technology. DSL service is not available everywhere, and it works better and faster the closer the installation is to the telephone provider's central office (CO). Also, DSL is much faster when receiving data over the Internet than it is when sending it. In some cases, the lines that are in place to carry telephone signals do not technically qualify to carry DSL signals. Cable Cable Internet connection does not use telephone lines. Cable uses coaxial cable lines originally designed to carry cable television. Like DSL, cable offers high speeds and an "always-on" connection, which means that even when the connection is not in use, the connection to the Internet is still available. Many cable companies offer telephone service as well. Because cable television reaches many homes, it is an alternative for people unable to receive DSL service. Theoretically, the bandwidth of cable is higher than DSL, but can be affected by limitations of the cable provider. Most homes that have cable television have the option to install high-speed Internet service. Satellite For people that live in rural areas, broadband satellite Internet connections provide a high-speed connection that is always on. A satellite dish is used to transmit and receive signals to and from a satellite that relays these signals back to a service provider. The cost of installation and the monthly service fees are much higher than those for DSL and cable subscribers. Heavy storm conditions can degrade the quality of the connection between the user and the satellite, or the satellite to the provider, slowing down or even disconnecting the connection. In most cases, the service provider provides a dial-up connection as a backup. Wireless Many types of wireless Internet services are available. The same companies that offer cellular service may offer Internet service. PCMCIA and PCI cards are used to connect a computer to the Internet. The service is not available in all areas. Service providers may offer wireless Internet service using microwave technology in limited areas. Signals are transmitted directly to an antenna on the roof of the house or building. Research the connection types that the ISPs offer before selecting an ISP. Check the services available in your area. Compare connection speeds, reliability, and cost before committing to a service agreement.  Worksheet ISP Connections Identify the best ISP based on a given scenario. this needs work Protocol Details Type Advantages Disadvantages POTS Speed Very slow speeds Cannot receive phone calls while connected Very common MAX 56 kbps Higher speeds than POTS ISDN Still much slower than other broadband technologies BRI – up to 128 kbps PRI – up to 2.048 Mbps DSL Low cost Must be close to carrier Cable 256 kbps – 24 Mbps Very high speed Slow upload speeds, 384 kbps – 27 Mbps Available when DSL and cable are not Satellite Significant lag, more expensive than other broadband technologies 9 kbps – 24 Mbps Security Chapter Introduction Wireless Scalable to customer needs Very expensive Limited market availability Up to 45 Mbps  15.3   Determine the components for your customer's network        15.3.3   Select network cards    table end Every device on a network requires a network interface. There are many types of network interfaces: list of 3 items • Most network interfaces for desktop computers are either integrated into the motherboard or are an expansion card that fits into an expansion slot. • Most laptop network interfaces are either integrated into the motherboard or fit into a PC Card or ExpressBus expansion slot. • USB network adapters plug into any available USB port and can be used with both desktops and laptops. list end Before purchasing a NIC, you should research the speed, form factor, and capabilities the card offers. Check the speed and capabilities of the hub or switch that will be connected to the computer. Ethernet NICs may be backward-compatible: list of 2 items • If you have a 10/100 Mbps NIC and a hub that is only 10 Mbps, the NIC will operate at 10 Mbps. • If you have a 10/100/1000 Mbps NIC and a switch that is only operating at 100 Mbps, the NIC will operate at 100 Mbps. list end However, if you have a gigabit switch, you will most likely need to purchase a gigabit NIC to match speeds. If there are any plans to upgrade the network in the future to Gigabit Ethernet, make sure to purchase NICs that are able to support the speed. Costs can vary greatly, so select NICs that match the needs of your customer. Wireless NICs are available in many formats with many capabilities. You should select wireless NICs based on the type of wireless network that is installed, as described in these examples: list of 3 items • 802.11b NICs can be used on 802.11g networks. • 802.11b and 802.11g NICs can be used on 802.11n networks. • 802.11a can be used only on a network that supports 802.11a. list end Choose wireless cards that match the needs of your customers. You should know what wireless equipment is in use and what will be installed on the network to ensure compatibility and usability. Wireless Network Interfaces USB PCI External PCMCIA  15.3   Determine the components for your customer's network        15.3.4   Select the network device     table end Several types of devices are available to connect components on a network. Select network devices to meet the needs of your customer. Hubs A hub is used to share data between multiple devices on a section of the network. The hub may connect to another networking device like a switch or router that connects to other sections of the network. The maximum speed of the network is determined by the speed of the hub. Hubs are used less often today because of the effectiveness and low cost of switches. Hubs do not segment network traffic, so they decrease the amount of available bandwidth to any device. In addition, because hubs cannot filter data, a lot of unnecessary traffic constantly moves between all the devices connected to it. One advantage of a hub is that it regenerates the data that passes through it. This means that a hub can also function as a repeater. A hub can extend the reach of a network because rebuilding the signal pulses overcomes the effects of distance. Switches In modern networks, switches have replaced hubs as the central point of connectivity. Like a hub, the speed of the switch determines the maximum speed of the network. However, switches filter and segment network traffic by sending data only to the device to which it is sent. This provides higher dedicated bandwidth to each device on the network. Switches maintain a switching table. The switching table contains a list of all MAC addresses on the network, and a list of which switch port can be used to reach a device with a given MAC address. The switching table records MAC addresses by inspecting the source MAC address of every incoming frame, as well as the port on which the frame arrives. The switch then creates a switching table that maps MAC addresses to outgoing ports. When a frame arrives that is destined for a particular MAC address, the switch uses the switching table to determine which port to use to reach the MAC address. The frame is forwarded from the port to the destination. By sending frames out of only one port to the destination, other ports are not affected, and bandwidth on the entire network is not affected. Routers Routers connect networks together. On a corporate network, one router port connects to the WAN connection and the other ports connect to the corporate LANs. The router becomes the gateway, or path to the outside, for the LAN. In a home network, the router connects the computers and network devices in the home to the Internet. In this case, the router is a home gateway. The wireless router, shown in Figure 1, serves as a firewall and provides wireless connectivity. When the home router provides multiple services, it may be called a multifunction device. ISP Equipment When subscribing to an ISP, you should find out what type of equipment is available so that you can select the most appropriate device. Many ISPs offer a discount on equipment that is purchased at the time of installation. Some ISPs may rent equipment on a month-to-month basis. This may be more attractive because the ISP supports the equipment if there is a failure, change, or upgrade to the technology. Home users may select to purchase equipment from the ISP because, after a period of time, the initial cost of the equipment will be lower than the cost of renting the equipment.   Activity Network Devices Complete the network device activity in Figure 2 graphic of Home Networking Devices Cable Modem Wireless Router Wireless Access Point 15.4 Implement the customer's network  Installing and implementing a network can be a complicated task. Even a small home network installation can become difficult and time consuming. However, careful planning helps ensure an easier and faster installation. During the installation, there may be some downtime for the existing network. For example, disruptions can be caused by building modifications and network cable installation. The project is not complete until all devices have been installed, configured, and tested. After completing this section, you will meet these objectives: list of 2 items • Install and test the customer's network. • Configure the customer's Internet and network resources. graphic Installation Checklist All parts are in Installation scheduled Backups are available Access to needed passwords Extra supplies handy Install components Test components  15.4   Implement the customer's network       15.4.2   Configure the customer's Internet and network resources    table end After the network has been set up and tested, you should configure a web browser, such as Microsoft Internet Explorer (IE). You can configure browser settings and perform maintenance tasks in the Internet Properties dialog box, as shown in Figure 1. Temporary Internet Files When an operating system such as Windows XP has been installed, IE is also installed by default. With IE, every time that you visit a website, many files are downloaded to your computer in the Temporary Internet Files folder. Most of these files are image files that represent banners and other components of the website. Temporary Internet files are stored on your computer so that the browser can load content faster the next time you visit a website that you have been to before. Depending on the number of websites you visit, the Temporary Internet Files folder can fill up quickly. While this may not be an urgent problem, you should delete, or flush out, the files occasionally. This is especially important after you have done online banking or have entered other personal information into the Web browser. Default Browser You can confirm which browser Windows uses by default. Choose Start > Run, enter a website address, and click OK. The website opens in the browser that is currently set as the default. If you want IE to be your default browser, start by opening IE. On the toolbar, select Tools > Internet Options… On the Programs tab, you can check to see if IE is your default browser, and select it if desired. File Sharing Users can share resources over the network. You can share a single file, specific folders, or an entire drive, as shown in Figure 2. To share a file, you should first copy it to a folder. Right-click the folder and select Sharing and Security. Next select Share this folder. You can identify who has access to the folder and what permissions they have on the objects in the folder. Figure 3 shows the permissions window of a shared folder. Permissions define the type of access a user has to a file or folder: list of 3 items • Read – Allows the user to view the file and subfolder names, navigate to subfolders, view data in files, and run program files. • Change – Allows all of the permissions of the Read permission but allows the user to add files and subfolders, change the data in files, and delete subfolders and files. • Full Control – Allows all of the permissions of Change and Read. If the file or folder is in an NTFS partition, Full Control allows you to change permissions on the file or folder, and take ownership of the file or folder. list end Windows XP Professional is limited to a maximum of 10 simultaneous file-sharing connections. Printer Sharing To share a printer, select Start > Control Panel > Printers and Faxes. Right-click the printer icon and select Sharing. Click Share this Printer and then click OK. The printer is now available for other computers to access. To access a printer shared by another computer, select Start > Control Panel > Printers and Faxes. Click File > Add Printer. Use the Add Printers wizard to find and install the shared network printer.  Lab Browser Configuration Configure an Internet browser Lab Network Resource Sharing Share and configure a network folder and printer 15.5 Upgrade the customer's network  You must be able to upgrade, install, and configure components when a customer asks for increased speed or new functionality to be added to a network. Devices such as wireless access points, wireless network cards, and faster network equipment and cable can be integrated into a network to allow the customer to communicate wirelessly or more quickly. If your customer is adding additional computers or wireless functionality, you should be able to recommend equipment based on their needs. The equipment that you suggest must work with the existing equipment and cabling, or the existing infrastructure must be upgraded. After completing this section, you will meet these objectives: list of 3 items • Install and configure wireless NIC. • Install and configure wireless routers. • Test connection. Network Upgrades Cable type Type of NIC Additional functionality (wireless, print server, etc.)  15.5   Upgrade the customer's network       15.5.1   Install and configure wireless NIC    table end To connect to a wireless network, your computer must have a wireless network interface. A wireless network interface is used to communicate with other wireless devices, such as computer, printer, or wireless access points. Before purchasing a wireless adapter, you should make sure that it is compatible with other wireless equipment that is already installed on the network. Also, verify that the wireless adapter is the correct form factor to fit in a desktop or laptop. A wireless USB adapter can be used with any desktop or laptop computer that has an open USB port. To install a wireless NIC on a desktop computer, you must remove the case cover. Install the wireless NIC into an available PCI slot or PCI express slot. Some wireless NICs have an antenna connected to the back of the card. Some antennas are attached with a cable so that they can be moved around or away from objects that may cause a poor connection. Once the wireless adapter is installed, there are additional configuration steps. These include configuring device drivers and entering network address information. When this is complete, the computer should be able to detect and connect to the wireless LAN. Wireless network adapters may use a wizard to connect to the wireless network. In this case, you would insert the CD that comes with the adapter and follow the directions to get connected.  Lab Wireless NIC Installation Install a wireless NIC  15.5   Upgrade the customer's network       15.5.2   Install and configure wireless routers    table end When installing a wireless network, you have to decide where you want to put access points, and then configure them. The following steps describe the installation of an access point: list of 6 items 1. Use a floor plan to find the locations for access points that allow maximum coverage. The best place for a wireless access point is at the center of the area you are covering, with a line of sight between the wireless devices and the access point. 2. Connect the access point to the existing network. On the back of the Linksys WRT300N router, there are five ports. Connect a DSL or cable modem to the port labeled "Internet". The switching logic of the device forwards all of the packets through this port when there is communication to and from the Internet and other connected computers. Connect one computer to any of the remaining ports to access the configuration web pages. 3. Turn on the broadband modem and plug in the power cord to the router. When the modem finishes establishing connection to the ISP, the router automatically communicates with the modem to receive network information from the ISP that is necessary to gain access to the Internet: IP address, subnet mask, and DNS server addresses. 4. When the router has established communication with the modem, you must configure the router to communicate with the devices on the network. Turn on the computer that is connected to the router. Open a web browser. In the Address field, enter 192.168.1.1. This is the default address for router configuration and management. 5. A security window prompts you for authentication to access the router configuration screens. The user name field should be left empty. Enter admin as the default password. When logged in, the first setup screen opens. 6. Continue with the setup. There are tabs that have sub-tabs on the setup screen. You must click Save Settings at the bottom of each screen after making any changes. list end When you use the configuration screens of the 300N router, you can click the help tab to see additional information about a tab. For information beyond what is shown on the help screen, consult the user manual.  Lab Wireless Router Installation Install a wireless router  15.5   Upgrade the customer's network       15.5.3   Test connection    table end It may be difficult to know if your wireless connection is working properly, even when Windows indicates that you are connected. You may be connected to a wireless access point or home gateway, but you may not be connected to the Internet. The easiest way to test for an Internet connection is to open a web browser and see if the Internet is available. To troubleshoot a wireless connection, you can use the Windows GUI or CLI. Network Connections To verify a wireless connection using the Windows XP GUI, select Start > Control Panel > Network Connections, as shown in Figure 1. Double-click on the wireless network connection to display the status. The Connection Status screen shown in Figure 2 displays the number of packets that have been sent and received. The packets are the communication between the computer and the network device. The window shows whether or not the computer is connected, along with the speed and duration of the connection. To display the Address Type, as shown in Figure 3, choose the Support tab on the Connection Status screen. The Connection Status information includes either a static address, which is assigned manually, or a dynamic address which is assigned by a DHCP server. The subnet mask and default gateway are also listed. To access the MAC address and other information about the IP address, click Details... . If the connection is not functioning correctly, click Repair to reset the connection information and attempt to establish a new connection. Ipconfig The ipconfig command is a command line tool that is used to verify that the connection has a valid IP address. The window displays basic IP address information for network connections. To perform specific tasks, add switches to the ipconfig command, as shown in Figure 4. Ping Ping is a CLI tool used to test connectivity between devices. You can test your own connection by pinging your computer. To test your computer, ping your NIC. Select Start > Run > cmd. At the command prompt, enter ping localhost. This command lets you know if your adapter is working properly. Ping your default gateway to check if your WAN connection is working properly. You can find the address for the default gateway by using the ipconfig command. To test the Internet connection and DNS, ping a popular website. Select Start > Run > cmd. At the command prompt, enter ping destination name. The response of the ping command displays the IP address resolution of the domain. The response shows replies from the ping or that the request timed out because there is a problem. Tracert Tracert is a CLI tool that traces the route that packets take from your computer to a destination address. Select Start > Run > cmd. At the command prompt, enter tracert. The first listing in the window for the tracert result is your default gateway. Each listing after that is the router that packets are traveling through to reach the destination. Tracert shows you where packets are stopping, indicating where the problem is occurring. If there are listings that show problems after the default gateway, it may mean that the problems are with the ISP, the Internet, or the destination server.  Lab Wireless NIC Connection Test Test the connection of the wireless NIC 15.6 Describe installation, configuration and management of a simple mail server  An e-mail system uses e-mail client software on the users' devices, and e-mail server software on one or more e-mail servers. Clients read e-mail from the e-mail server using one of two protocols: list of 2 items • Post Office Protocol (POP) • Internet Message Access Protocol (IMAP) list end Clients send e-mail to an e-mail server, and e-mail servers forward e-mail to each other, using Simple Mail Transfer Protocol (SMTP). You need to know how to configure a client computer to accept the correct incoming mail format, and also understand the process for setting up a mail server. Configuring the e-mail client software can be done using connection wizards such as shown in Figure 1. The advantages and disadvantages of each e-mail protocol are shown in Figure 2. SMTP SMTP sends e-mail from a e-mail client to an e-mail server, or from one e-mail server to another. SMTP has these characteristics: list of 4 items • Simple, text-based protocol • Sent over TCP using port 25 • Must be implemented to send e-mail • Message is sent after receipients are identified and verified list end POP Post Office Protocol (POP) is used by an e-mail client to download e-mail from an e-mail server. The most recent version of POP is POP3. POP3 usually uses port 110. POP3 supports end users that have intermittent connections, such as dial-up. A POP3 user can connect, download e-mail from the server, delete the e-mail, and then disconnect. IMAP Internet Message Access Protocol (IMAP) is similar to POP3, but has additional features. Like POP3, IMAP allows you to download e-mail from an e-mail server using an e-mail client. The difference is that IMAP allows the user to organize e-mail on the network e-mail server. IMAP is faster than POP3 and requires more disk space on the server and more CPU resources. The most recent version of IMAP is IMAP4. IMAP4 is often used in large networks such as a university campus. IMAP usually uses port 143. E-mail Server An e-mail server is a computer that can send and receive e-mail on behalf of e-mail clients. These are some common e-mail servers: list of 3 items • Microsoft Exchange • Sendmail • Eudora Internet Mail Server (EIMS) list end As shown in Figure 3, there are often wizards and tools available to guide you in setting up an e-mail server. To install and set up an e-mail server, such as Microsoft Exchange, you must first make sure that the network has all of the proper qualifications in place and that it is properly configured. Active directory servers, global catalog servers, and domain name servers (DNS) must all be in place and functioning before Exchange can be installed and work properly. An active directory server is a computer that hosts a database that allows centralized administration over an enterprise network. A global catalog server is a centralized repository that contains information about every domain in an enterprise network. Exchange must be installed on a domain where every computer runs at least Windows 2000. This is known as native mode. Windows NT domain controllers cannot function in a native environment. The Active Directory database is organized in a pattern called a schema. One server running Windows 2003 is designated as the Schema Master. This is the only server that can change the way the Active Directory user database is organized. When the network administrator needs to modify the Active Directory structure, the change is made on the Schema Master. Active Directory then automatically copies the update to all the rest of the authentication servers. E-mail Server Installation You should test the environment before you install Exchange. To prevent the installation from affecting the daily operation of your network, set up the services required and install Exchange on a dedicated set of servers away from the main network. Keep the installation of Exchange separated from your production network until you are sure that it is functioning properly. Before you install Exchange, be prepared with the proper equipment and information: list of 8 items • Fully functional and reliable DNS deployment • Active Directory domain • At least one Global Catalog • Windows 2000 or higher native domain functionality • Exchange server software • Windows server support tools • Schema master server • High-speed Internet connection list end You are ready to install the mail server when all of the qualifications of your network are in place. You will have to add Internet Information Services (IIS) using the Add/Remove Windows Components wizard before initiating the installation of the Exchange server. IIS is a server that has programs used for building and administering website services. After IIS has been installed, Exchange can be installed. Insert the installation CD and begin the New Exchange installation wizard. The installation wizard will take you through a series of steps to verify that Exchange is ready to be installed. The wizard will check to make sure that IIS is installed, the domain servers are running properly, and the Windows support tools are installed. The setup program will notify you of any problems with the installation environment. Restart the setup program from the beginning after fixing any issues. Once Exchange is installed, the Microsoft Management Console plug in for Exchange, shown in Figure 4, will provide access to many settings at one convenient location. Make sure to install all updates so that the server will run properly. The Exchange System Manager, which is a console that controls the Exchange deployment, can be used to manage the options of the server. Use the Active Directory Users and Computer (ADUC) console to configure a user's mailbox. This is also known as making the user "mailbox-enabled". Open the ADUC to create a new user. Fill out the username and password information according to the domain security policy, as shown in Figure 5. The user's mailbox will be created by the exchange server when the user receives the first e-mail. Setting up Exchange takes careful planning, including ensuring that the servers, services, and technologies are in place and working correctly on the network. In some cases, during an installation, if there is a failure, you may need to reinstall the operating system and start the Exchange installation from the beginning. NOTE:Before planning an e-mail server installation, consult with network professionals, experienced Windows networking experts, or experienced e-mail technicians. 15.7 Describe preventive maintenance procedures for networks  Preventive maintenance is just as important for the network as it is for the computers on a network. You must check the condition of cables, network devices, servers, and computers to make sure that they are kept clean and are in good working order. You should develop a plan to perform scheduled maintenance and cleaning at regular intervals. This will help you to prevent network down-time and equipment failures. As part of a regularly scheduled maintenance program, inspect all cabling for breaks. Make sure that cables are labeled correctly and labels are not coming off. Replace any worn or unreadable labels. Check that cable supports are properly installed and no attachment points are coming loose. Cabling can become damaged and worn. You should keep the cabling in good repair to maintain good network performance. As a technician, you may notice if equipment is failing, damaged, or making unusual sounds. Inform the network administrator to prevent unnecessary network downtime. Cables at workstations and printers should be checked carefully. Cables are often moved or kicked when they are underneath desks, and can be bent. These conditions can result in loss of bandwidth or connectivity. You should also be proactive in the education of network users. Demonstrate to network users how to properly connect and disconnect cables, as well as how to move them if necessary. 15.8 Troubleshoot the network   To begin troubleshooting a network problem, you should first try to locate the source of the problem. Check to see if a group of users or only one user has the problem. If the problem is with one user, begin troubleshooting the problem starting with their computer. After completing this section, you will meet these objectives: list of 3 items • Review the troubleshooting process. • Identify common problems and solutions. • Apply troubleshooting skills.  15.8   Troubleshoot the network        15.8.1   Review the troubleshooting process    table end Network problems can result from a combination of hardware, software, and connectivity issues. Computer technicians must be able to analyze the problem and determine the cause of the error in order to repair the network issue. This process is called troubleshooting. The first step in the troubleshooting process is to gather data from the customer. Figures 1 and 2 list open-ended and closed-ended questions to ask the customer. Once you have talked to the customer, you should verify the obvious issues. Figure 3 lists issues that apply to networks. After the obvious issues have been verified, try some quick solutions. Figure 4 lists some quick solutions to network problems. If quick solutions did not correct the problem, it is time to gather data from the computer. Figure 5 shows different ways to gather information about the network problem. At this point, you will have enough information to evaluate the problem, research, and implement possible solutions. Figure 6 shows resources for possible solutions. After you have solved the problem, you will close with the customer. Figure 7 is a list of the tasks required to complete this step. List of open-ended questions about network errors. (This list is NOT comprehensive.) When did the problem start? What problems are you experiencing? Is there anything else you can tell me about the problem? What other users are having the problem? What type of equipment is having the problem? What are the effects of the problem? Describe your work environment? When did you last back up your computer? What type of backup was performed? What group are you a member of?  15.8   Troubleshoot the network        15.8.2   Identify common problems and solutions    table end Network problems can be attributed to hardware, software, networks, or some combination of the three. You will resolve some types of problems more often than others. Figure 1 is a chart of common network problems and solutions. Common Problems and Solutions Problem Symptom Possible Solution Users report that a network printer is increasingly unreliable. The network cable travels under a desk and has become frayed and pinched. Replace and reroute the network printer cable. The user’s Connection Status screen shows less than a dozen packets sent and received, even though the computer has been on for hours. The wireless connection has failed. Reset the wireless adapter card, click Repair to refresh the IP address, and check again. A user is making many changes in the configuration of a WRT300N wireless router, but the changes do not seem to remain in effect. The user must click Save Settings at the bottom of each screen after making any changes. A user receives a warning message that hard drive space is low. Locate the folder where webbrowser or temporary files are stored and verify the folder size is a problem. Use Disk Cleanup to delete the temp files, the browser clean up utility, or manually delete them. A network has become slow as more users are added. All users connect to a 24-port hub. Replace the hub with a switch.  15.8   Troubleshoot the network        15.8.3   Apply troubleshooting skills    table end Now that you understand the troubleshooting process, it is time to apply your listening and diagnostic skills. The first lab is designed to reinforce your skills with networks. You will will troubleshoot and fix a computer that does not connect to the network. The second lab is designed to reinforce your communication and troubleshooting skills. In this lab, you will perform the following steps: list of 3 items • Receive the work order • Take the customer through various steps to try and resolve the problem • Document the problem and the resolution list end   Lab Network Problem Correct a network problem Lab Remote Tech Network Problem Instruct a customer on how to correct a network problem 15.9 Summary  The advanced networks chapter discussed the planning, implementation, and upgrading of networks and network components. The following are some of the important concepts to remember from this chapter: list of 8 items • There are many safety hazards associated with network environments, devices, and media. You should follow proper safety procedures at all times. • Networks must be designed around the needs of your customer. Make design decisions that will meet the needs and the goals of your customers. • Select network components that offer the services and capabilities necessary to implement a network based on the needs of the customer. • Plan network installations based on the services and equipment necessary to provide the network that is needed. • Upgrading a network may involve additional equipment, advanced equipment, or cabling. Discuss how upgrading can help to enhance the usability of the network in the future. • Plan for an e-mail installation before deployment. Consult a specialist to make sure the installation and configuration of an e-mail server goes smoothly. • Prevent network problems by developing and implementing a solid preventive maintenance policy. • Follow a logical methodology to troubleshoot advanced network problems.