Troubleshoot Network Connectivity Issues

Introduction

The Troubleshoot Connectivity Issues with TCP/IP Utilities module provides you with the instruction and server hardware to develop your hands on skills in the defined topics. This module includes the following exercises:

• Using Ipconfig
• Using Tracert
• Using Netstat
• Using Nslookup
• Using Pathping
• Using Nbtstat
• Using Arp
• Using Ping

Exam Objectives

The following exam objectives are covered in this lab:

• 220-902: 4.4 Given a scenario, troubleshoot wired and wireless networks with appropriate tools (Command line tools)

Lab time: It will take approximately 1 hour to complete this lab.

Exercise 1 - Using Ipconfig

Ipconfig is the short form of internet protocol configuration. It is a tool used to display all existing TCP/IP network configuration values. The tool is also used to change settings of Dynamic Host Configuration Protocol (DHCP) and Domain Name System (DNS). In ipconfig tool, the command switch/all provides more detailed information than ipconfig.

The parameter /release releases the IP address for the specified adapter from DHCP server. The parameter /renew renews the IP address for the specified adapter from DHCP server.

Exercise 2 - Using Tracert

Tracert or the trace route command is a TCP/IP tool that you can use for displaying the path that an Internet Protocol (IP) packet takes to reach the destination node.

This tool can be used locally to find out the path from your local host to another device your corporate network or to the Internet. In addition, there are web-based third party tools that can show the network route from a local device to a distant server that runs a service like World Wide Web service.

Exercise 3 - Using Netstat

Network statistics or netstat is a command-line tool which is used to view network connections, network protocol statistics, routing tables and network interface such as network interface controller or software-defined network interface. It helps in measuring performance by finding network errors and determining the network traffic.

Exercise 4 - Using NSLOOKUP

Name server lookup or NSLOOKUP is a built-in tool in Windows which is used for querying Domain Name System (DNS) server and view the resource records like hostnames and IP addresses of devices registered in a domain.

NSLOOKUP can be used in interactive mode, where you will enter the nslookup context by simply typing nslookup and start entering commands supported by this DNS diagnostic tool.

NSLOOKUP can be used in non-interactive mode, by simply typing nslookup in the command line and use the appropriate parameters to query DNS server for the required resource records.

There are web-based NSLOOKUP tools available on the Internet. These tools however provide minimal details of the target domain that you are trying to lookup for security reasons.

Exercise 5 - Using Pathping

Pathping is a Windows-based TCP/IP diagnostic tool that provides information about the network path, network delays and dropped packets from the source to the destination network. This tool combines the functionality of tracert and ping commands to verify connectivity between devices.

Exercise 6 - Using Arp

Address resolution protocol (ARP) is a TCP/IP protocol that maps a computer’s IP address to its Ethernet or Media access control (MAC) address.

When Host A needs to send information to Host B, Host A will use Domain Name System (DNS) to find HostB. HostA will look up its ARP cache and find out the hardware address of HostB to allow it to send data directly to the host.

Exercise 7 - Using Ping

Packet Internet Groper (ping) is a TCP/IP utility used for verifying the reachability of a host or network by sending packets that measure that round-trip time from the source to the destination and back.

Ping sends out Internet Control Message Protocol (ICMP) to the target system like an echo request and waits for an echo reply from the remote host.

Exercise 8 - Using Nbtstat

NetBIOS over TCP/IP (NBTSTAT) is a Windows TCP/IP utility for resolving NetBIOS name resolution issues. On a typical Windows network, NetBIOS over TCP/IP resolves NetBIOS names using a local cache, WINS, broadcast, HOSTS file and DNS server query.

On this exercise, you will use NBTSTAT to resolve some common problems on NetBIOS name resolution.