Network baselines are a series of measurements of network performance taken during different types of network usage. The baselines help to understand the parameters of a properly working network so that network performance or security problems can be identified when performance deviates significantly from previous baseline measurements.
Cisco Discovery Protocol (CDP) is a Cisco protocol that runs on Cisco networking devices. It sends CDP advertisements to directly attached neighbor devices. Information sent in these advertisements include the configured device name, a port identifier, the hardware platform and software versions, and IP addresses. This information is displayed with the IOS commands show cdp neighbors and show cdp neighbors detail. CDP can be used to reveal information about network topologies.
• Help Desks—Security policies specify what employees need to do to ensure that the network is secure. This includes policies regarding user identification and authentication, password length, complexity and refresh interval, acceptable behavior, and remote-access requirements. Standard operating procedures (SOPs) define procedures that must be followed for replacing network devices, installing or removing software applications, new employee onboarding, and employee termination. Guidelines are suggestions for proper procedure that exist when no SOPs are defined.
A help desk is a specialized team of IT professionals that are the central point of contact for employees and customers who need technical assistance. Help desks use communication tools such as chat, telephone, or email to receive issues from customers and facilitate the troubleshooting process. A ticketing system is used to manage “trouble tickets” that consist of details of the issues that users report. Users initiate the tickets, and technicians validate the issues, work with users to address the issues, and escalate the tickets if a higher degree of expertise is required to resolve the issues.
A support technician should always be considerate and should empathize with users, who may be under stress and anxious to resolve a problem quickly. Technicians should never belittle, insult, or talk down to users, or accuse users of causing the problem.
The know, relate, and understand skill set is a useful way to relate to customers. To know the customer, call them by their name or ask if there is another name that you can use. To better relate to the customer, attempt to create a one-on-one connection. And to understand the customer, determine their level of technical knowledge as a way to speak to them at an appropriate level. Questioning is important using either open-ended or closed-ended questions. Active listening entails using understanding responses as users talk and summarizing what they tell you to verify your understanding.
When addressing an issue with hosts, gather information about the device, operating system, network environment, and the results of connectivity tests, such as ping and tracert. Other sources of information are beep codes, Event Viewer logs, Device Manager settings, Task Manager data, and diagnostic tool results.
For Cisco device–related tickets, use IOS commands, packet captures, and device logs to gather information. IOS commands for connectivity testing, such as ping and traceroute, are useful. Secure Shell (SSH) is the preferred way to connect to the IOS CLI remotely because Telnet is not secure. IOS show commands, such as show ip interface brief, show ip route, and show protocols, are useful also.
The next step in the troubleshooting process is to analyze the information that you have gathered and solve the problem. You can consult the ticket system software to locate similar issues, access vendor information resources and FAQs, and search the Internet for relevant information. If you can’t solve the problem, then you should escalate it to a higher-level technician for resolution.
• Troubleshoot Endpoint Connectivity—To verify the network configuration of a Windows host, check the status of the connections in Network and Sharing Center. You can also use ipconfig /all to display this information. Use ping and traceroute or tracert to test connectivity.
On a Linux host, you can view active connections in the GUI or use the ifconfig command in a terminal. In addition to ping and traceroute, other command-line tools such as speedtest and ncat (nc) are available for network testing.
In macOS, open Network Preferences > Advanced to get IP addressing information. The ifconfig command can be issued from a terminal as well. Other useful commands are networksetup -listallnetworkservices and networksetup -getinfo <network service>. The Linux commands mentioned above are also available in macOS. The macOS Wireless Diagnostics tool can also help solve connectivity problems.
Apple iOS networking can be verified by accessing the Wi-Fi settings. In Android, information about the device addressing and connections can be accessed from the About phone > Status settings. Third-party apps are available that enhance networks diagnostics for Android.
• Troubleshoot a Network—To gather information to troubleshoot a network problem, Cisco IOS devices have many show commands that can provide detailed information. The Cisco IOS software separates management access into two privilege levels: user EXEC mode, which is lower level, and privileged EXEC mode, which has full privileges. Use the enable command to enter Cisco privileged EXEC mode. IOS context-sensitive help can be used to locate commands and get information about their usage. Context-sensitive help is available by entering a ? at an empty prompt or after a command.