When a Level 1 support desk technician receives a call, there is a process followed to gather information. There are also specific systems for storing and retrieving relevant information. It is extremely important to gather the information correctly in the event that a call has to be escalated to a Level 2 technician or require an onsite visit.

The information gathering and recording process starts as soon as the technician answers the phone. After customer identification, the technician accesses the relevant customer information. Typically, a database application is used to manage the customer information.

The information is transferred to a trouble ticket, also known as an incident report. This document can be a piece of paper in a paper filing system or an electronic tracking system designed to follow the troubleshooting process from beginning to end. Each person who works on the problem is expected to record what was done on the trouble ticket. When an onsite call is required, the trouble ticket information can be converted to a work order that the onsite technician can take to the customer site.

When a problem is resolved, the solution is documented in the customer work order (see Figure 20-14) or trouble ticket, and in a knowledge base document for future reference.

   

Figure 20-14 A Work Order

Summary (20.7)

Packet Tracer—Skills Integration Challenge (20.7.1)

This activity includes many of the skills that you have acquired during your Networking Essentials studies. First, you will configure the IP addresses on network devices in a simplified network. Second, you will set up the wireless configurations in a home network. Finally, you will verify your implementation by testing end-to-end connectivity by accessing the web server and router R1 using SSH in the simplified network.

The following is a summary of each topic in the chapter:

• The Troubleshooting Process—Troubleshooting is the process of identifying, locating, and correcting problems that occur. You can use structured techniques to determine the most probable cause and solution. Be sure to document all steps taken in troubleshooting, even the ones that did not solve the issue.

To gather information about a problem, start by talking to the individual who reported the problem as well as any other affected users. Next, collect information about any equipment that may be affected. This information can be gathered from documentation. A copy of all log files and a listing of any recent changes made to equipment configurations are also necessary. Information about the network can also be gathered using network monitoring tools.

Choose a troubleshooting approach to organize your efforts to fix the problem. Three structured troubleshooting techniques include top-down, divide-and-conquer, and bottom-up. All of these structured approaches assume a layered concept of networking. Other good approaches are follow-the-path, substitution, comparison, and educated guess.

• Physical Layer Problems—Physical layer problems are concerned mainly with the hardware aspects of computers and networking devices and the cables that interconnect them. To troubleshoot at Layer 1, first check that all devices have power supplied and that the devices are turned on. If the problem is with wireless, verify that the wireless access point is operational and that wireless settings are configured correctly.

Regardless of whether the fault is present on the wireless or wired network, one of the first steps in a bottom-up strategy of troubleshooting should be to examine the LEDs, which indicate the current state or activity of a piece of equipment or connection. Cabling is the central nervous system of wired networks and one of the most common causes of connectivity problems. Be sure to use the correct type of cable. Improper cable termination is one of the main problems encountered in networks. To avoid this, all cables in the network should be terminated according to the same standard. Maximum cable run lengths exist based on characteristics of the different cables. Verify that the correct ports are being used between the networking devices. Protect cables and connectors from physical damage.

• Troubleshooting Commands—A number of software utility programs are available to help you identify network problems. Some of the available utilities include ipconfig, ping, netstat, tracert, and nslookup.

On Windows devices, you can view the IP configuration information with the ipconfig command at the command prompt. If the IP configuration appears to be correctly configured on the local host, test network connectivity by using ping, which tests whether a destination host is reachable.

When troubleshooting a network with both wired and wireless connections, use a divide-and-conquer technique to isolate the problem to either the wired or wireless network. The easiest way to determine if the problem is with the wired or the wireless network is to

• Ping from a wireless client to the default gateway. This verifies whether the wireless client is connecting as expected.
  • Ping from a wired client to the default gateway. This verifies whether the wired client is connecting as expected.
  • Ping from the wireless client to a wired client. This verifies whether the wireless router is functioning as expected.

The tracert utility provides connectivity information about the path a packet takes to reach the destination and about every router (hop) along the way. It also indicates how long a packet takes to get from the source to each hop and back (round trip time). tracert can help identify where a packet may have been lost or delayed due to bottlenecks or slowdowns in the network.

Sometimes you need to know which active TCP connections are open and running on a networked host. netstat is an important network utility that can be used to verify those connections. It lists the protocol in use, the local address and port number, the foreign address and port number, and the state of the connection.

The nslookup utility enables you to look up information about a particular DNS name in the DNS server. When the nslookup command is issued, the information returned includes the IP address of the DNS server being used as well as the IP address associated with the specified DNS name. nslookup is often used as a troubleshooting tool for determining whether the DNS server is performing name resolution as expected.

• Troubleshoot Wireless Issues—Wireless communications rely on RF signals to carry data. Many factors can affect your ability to connect hosts using RF:
  • Not all wireless standards are compatible.
  • Each wireless conversation must occur on a separate, nonoverlapping channel.
  • The strength of an RF signal decreases with distance.
  • RF signals are susceptible to interference from outside sources, including other devices functioning on the same frequency.
  • APs share the available bandwidth between devices.

Modern WLANs incorporate various technologies to help secure the data on the WLAN. Incorrect configuration of any of them can prevent communication. Some of the most common settings that are configured incorrectly include the SSID, authentication, and encryption.

• Common Internet Connectivity Issues—If the physical connection to the wired or wireless host appears to be connecting as expected, check the IP configuration of the client. In most cases, the wireless router receives its own IP address through DHCP from the ISP. Check to make sure that the router has an IP address, and attempt to release and renew the address using the GUI utility.

If hosts on the wired and wireless local network can connect to the wireless router and with other hosts on the local network but not to the Internet, the problem may be in the connection between the router and the ISP. Using the GUI, one way to check connectivity is to examine the router status page. It should show the IP address assigned by the ISP and should indicate whether the connection is established. If this page shows no connection, the wireless router may not be connected. If the wireless router still does not connect, contact the ISP to see whether the issue is occurring from that end.

If a network firewall is used along the path, it is important to check that the application TCP or UDP port is open and no filter lists are blocking traffic to that port. If all clients are obtaining the correct IP configuration and can connect to the wireless router but are unable to ping each other, or cannot access a remote server or application, the problem may be with rules on the router. Check all settings on the router to ensure no security restrictions could be causing the issue. Verify that the local firewalls on the client devices are not preventing network functionality.

• Customer Support—Some of the most common sources for help include previously kept documentation, online FAQs, colleagues and other network professionals, and Internet sources including forums, articles, and blogs. The support desk is a group of individuals with the knowledge and tools required to help diagnose and correct common problems. If necessary, the support desk can take control of a local host through remote-access software. The support desk requires information specific to the problem, including symptoms encountered, who encountered the problem, when the problem manifests, steps taken to identify the problem, and results of steps taken.

If first-level support desk staff are unable to solve the problem, they may escalate the problem to a higher level. Higher-level staff are generally more knowledgeable and have access to resources and tools that the first-level support desk staff do not. Record all information regarding the interaction with the support desk, such as time/date of call, name/ID of technician, problem reported, course of action taken, resolution/escalation, and next steps.

When a Level 1 support desk technician receives a call, the technician follows a process to gather information. There are also specific systems for storing and retrieving relevant information. It is extremely important to gather the information correctly in the event that a call has to be escalated to Level 2 or require an onsite visit. The information is transferred to a trouble ticket, also known as an incident report. When a problem is resolved, the solution is documented in the customer work order or trouble ticket and in a knowledge base document for future reference.