Computer Networks & Troubleshooting Tools PDF

Experiment#01 Introduction to Computer Networks and Windows Network Troubleshooting Tools Part #1: Objectives: Introduction to Computer networks. Describe the functions and physical characteristics of the network device. Describe the functions and physical characteristics of...

Experiment#01 Introduction to Computer Networks and Windows Network Troubleshooting Tools Part #1: Objectives: Introduction to Computer networks. Describe the functions and physical characteristics of the network device. Describe the functions and physical characteristics of the media. Background / Scenario: A computer network is a group of computer systems and other devices that are linked together through communication channels or media to facilitate communication and resource-sharing among a wide range of users. Components of a computer network: There are three categories of network components: 1. Devices ▪ End devices (computer, printer, security cameras, etc.) ▪ Intermediary devices (router, switch, hub, firewalls) 2. Media ▪ Wired Cooper (UTP, STP) Fiber optic (multimode fiber , single mode fiber) ▪ Wireless 3. Services As a member of the networking support staff, you must be able to identify different networking equipment. You must also understand the function of equipment in the appropriate part of the network. In this lab, you will have access to network devices and media. You will identify the type and characteristics of the network equipment and media. Identify Network Devices Fill in the table below with the device tag ID number, manufacturer, device model, type (hub, switch, and router), functionality (wireless, router, switch, or combination), and other physical characteristics, such as number of interface types. The first line is filled out as a reference. 1 ID Manufacturer Model Type Functionality Physical Characteristics 2 GigabitEthernet Ports 2 EHWIC slots 1 Cisco 1941 Router Router 2 CompactFlash slots 1 ISM slot 2 Console ports: USB, RJ-45 2 3 4 5 6 Identify Network Media: You will name the network media, identify the media type (copper, fiber optic, or wireless), and provide a short media description including what device types it connects. Use the table below to record your findings. The first line in the table has been filled out as a reference. 2 ID Network Media Type Description and to What It Connects Connect wired NIC and Ethernet ports on network devices 1 UTP Copper Cat 5 straight-through wired. Connects PCs and routers to switches and wiring panels. 2 3 4 5 6 Reflection After you have identified the network equipment, where would you find more information about the equipment? ____________________________________________________________________________________ ____________________________________________________________________________________ ____________________________________________________________________________________ ____________________________________________________________________________________ 3 Part#2: Objective: Windows Network Troubleshooting Tools Back Ground Scenario: If you call technical support about problems with your network or Internet connection, they will most likely have you use some or all of these utilities. You should check all of the hardware connections as well. Refer to the Network Connections handout for a detailed description of networking connections. Some Useful Connectivity Utilities : ipconfig – (IP configuration) Use ipconfig to find the IP address and configuration of your own computer and network. By default, ipconfig only displays the IP address, subnet mask, and default gateway. For more in depth information, add the text /all after ipconfig. You will be able to view all of the IP configuration information for the computer. ping – (packet internet groper) A utility to determine whether a specific IP address is accessible. It works by sending a packet of data to the specified address and waiting for a reply. If you are having difficulty accessing the Internet, try using the ping command to connect to the different network nodes to narrow down where the problem could be coming from. For instance, if you are able to ping the network card, but not the router, the problem is most likely local. If you can ping everywhere except for a certain outside address, the problem is remote. Syntax: ping IP address or domain tracert – (trace route) A utility that traces a packet from your computer to an Internet host, showing how many hops the packet requires to reach the host and how long each hop takes. If you're visiting a Web site and pages are appearing slowly, you can use trace route to figure out where the longest delays are occurring. Syntax: tracert IP address or domain nslookup – (name server lookup) Nslookup is the name of a program that lets an Internet server administrator or user enter a host name (for example, www.yahoo.com) and find out the corresponding Internet address. It will also do reverse name lookup and find the host name for an IP address you specify. Nslookup sends a domain name query packet to a designated (or defaulted) Domain Name System (DNS) server. Depending on the system you are using, the default may be the local DNS name server at your service provider, some intermediate name server, or the root name server (at InterNIC) for the entire domain name system hierarchy. Syntax: nslookup IP address or domain 4 Using Ipconfig: 1. Log on to the computer as a user with administrative rights. 2. Click Start and select Run (Windows Vista or Windows 7 Click the “Start” button and type in the “Search for Programs and Files” text box). 3. Type cmd and press ENTER. The black Command Prompt window will appear. 4. Type ipconfig at the command prompt and press ENTER. The following screenshot gives an example of the information shown when using “ipconfig”. 5. Write down any configuration information you will need. At a minimum, it will be the IP address of your computer and the Default Gateway. 6. Sometimes you might need more information and you can add the “/all” to the above “ipconfig” command. This screenshot gives an example of the information shown when using “ipconfig /all”: 5 Using Ping: 1. Log on to the computer as a user with administrative rights. 2. Click Start and select Run (Windows Vista or Windows 7 Click the “Start” button and type in the “Search for Programs and Files” text box). 3. Type cmd and press ENTER. The black Command Prompt window will appear. 4. Type ping IP address or domain and press ENTER. If you are unable to ping a destination, first check to see that there are no typing errors. If the address is correct, use the Troubleshooting Routing Errors table below to examine what the cause could be. A successful ping looks similar to this: Use any or all of the following address options to determine where the connection is failing. ping the Ethernet card (NIC) in your computer — this will always be 127.0.0.1 ping your own computer —use ipconfig to look up the IP address, if necessary. ping the Default Gateway (router) — you can find the Default Gateway on the computer in the same spot as the IP address. ping an outside IP address — for example the Level3 DNS Server 4.2.2.2. ping a domain name to check DNS — for example: ping www.google.com. Troubleshooting Ping Errors Once all of the hardware connections are checked and verified, any of the following could be the cause of your networking error(s). Symptom Possible Causes Unable to ping the NIC. The NIC is disabled or faulty. Unable to ping your own computer. The IP address is incorrect. The computer is disconnected from the network. Unable to ping the Default Gateway. The Default Gateway is down. The gateway address used in ping is incorrect. The gateway is not attached to the subnet. The outside server is offline. Unable to ping an outside IP address. The IP address was typed incorrectly. A packet is routed incorrectly between the source and destination networks. The DNS server is not working. Unable to ping a domain name. The destination server is offline. Internet traffic is heavy. Internet connections are slow and or intermittent. There are problems with the line. Contact the phone or cable company. 6 Using Tracert: 1. Log on to the computer as a user with administrative rights. 2. Click Start and select Run (Windows Vista or Windows 7 Click the “Start” button and type in the “Search for Programs and Files” text box). 3. Type cmd and press ENTER. The black Command Prompt window will appear. 4. Type tracert IP address or domain and press ENTER. The following screenshot shows an example using nslookup. Tracert returns results in milliseconds (ms). Ideally, every hop should give an IP address and time. After requesting information from the DNS server, the first hop is to the default gateway. The hop to the default gateway should take 10-20 ms. After that, hops should take anywhere from 80-120ms. Errors indicated by * on the route can show where there is a lot of network traffic or possible line problems Using Nslookup: 1. Log on to the computer as a user with administrative rights. 2. Click Start and select Run (Windows Vista or Windows 7 Click the “Start” button and type in the “Search for Programs and Files” text box). 3. Type cmd and press ENTER. The black Command Prompt window will appear. 4. Type nslookup IP address or domain and press ENTER. The following screenshot shows two examples using nslookup. The first looks up an IP address (4.2.2.2) while the second looks up a domain name (www.yahoo.com). Server: the local DNS server used to look up the information. Address: the IP address of the local DNS server. Name: The domain name of the server hosting the remote domain or IP. Address(s): The IP address(s) of the remote server. Aliases: The common name(s) used to identify multiple IP addresses or domain names. 7  Lab’s Evaluation Sheet Students Registration No: Date Performed: Group No: Date of Submission: Marks /Grade Sr. No. Categories Total Marks/Grade Obtained 1 Student’s Behavior 2.5 2 Lab Performance 2.5 3 On Time Submission 5 4 Home Activity 10 Net Result 20 Examined By: (Instructor’s Name & Initial’s) Date 8