12.11 Windows Specific Networking Software Connection Troubleshooting
12.11.9 Network troubleshooting software utilities
To help troubleshoot network issues, Windows has provided a few useful tools to identify why an end user is unable to access the network. Some of more common ones were mentioned in Chapter 8, "Networking Fundamentals". Use these tools to test connections, settings, and trace the route of where the packets are being sent on the network to identify where the problem lies and what the problem is.

PING.EXE
This utility is short for Packet Internet Groper. It is used to determine whether a specific IP address is accessible. It works by sending a packet to the specified address and waiting for a reply. PING is used primarily to troubleshoot Internet and network connections.

TRACERT.EXE
TRACERT.EXE is a utility that traces a packet from the computer to an Internet host. It shows how many hops the packet requires to reach the host and how long each hop takes. A hop is when a packet travels from one router to another. If website pages are appearing slowly, use TRACERT.EXE to identify where the longest delays are occurring.

TRACERT.EXE utilities work by sending packets with low Time-to-Live (TTL) fields. The TTL value specifies how many hops the packet is allowed before it is returned. When a packet cannot reach its destination because the TTL value is too low, the last host returns the packet and identifies itself. By sending a series of packets and increasing the TTL value with each successive packet, TRACERT.EXE finds out who all the intermediary hosts are.

WINIPCFG.EXE
WINIPCFG.EXE stands for Windows IP Configuration. It is a tool that allows the technician to view the basic IP networking settings of a Windows 95, Windows 98, or Windows ME computer. This will not work on NT or 2000 systems. Technicians will have to use IPCONFIG.EXE on NT and 2000 machines instead. IP addresses (one of which each computer must have in order to interact with the Internet) are assigned manually or allocated and assigned by the Dynamic Host Configuration Protocol (DHCP). When the system boots up, it sends a message to the DHCP servers saying that it needs an IP address. A DHCP server finds one that is not in use and assigns it to the computer.

The winipcfg utility lets the technician get a new set of IP information (such as an address, mask, gateway) without rebooting. Do this by selecting the Release button, which will release the IP information. Then select the Renew button that will assign the computer a new IP address from the DHCP server. Again, this can be done without having to reboot the system. Frequently, grabbing new information can help with IP-related problems.

To run winipcfg, select Run from the Start menu and type "winipcfg" into the Open: box. Then hit the OK button. Or do this from a DOS prompt.

IPCONFIG.EXE
The IPCONFIG.EXE utility is the Windows NT/2000 equivalent of the WINIPCFG.EXE command in Windows 95, 98, and ME. It performs the same functions as the WINIPCFG.EXE command in that it allows users to view all the IP address information as well as the WINS server addresses, DNS server addresses, and the DHCP server addresses. Use the /release or the /renew switches to obtain new IP addresses. The main difference is that the IPCONFIG.EXE command must run from the DOS prompt. It cannot be typed in the Run command windows on the Start menu like the WINIPCFG.EXE command.

NET VIEW Command 
The Net View command will display a list of domains, a list of computers, and a list of resources for a computer. The Net View command is a command-line interface that performs essentially all of the browsing functions available in Network Neighborhood or My Computer, except that a user cannot view a list of workgroups.

The syntax for the Net View command is: net view [\\computername | /domain[:domainname]], where net view without parameters will display a list of computers in the domain. \\computername is the computer name whose resources (shares) are to be displayed. /domain[:domainname] is the domain whose computer names are to be viewed. Using /domain will display all domain names on the network. Type these commands from the DOS prompt.

NETSTAT
The NetStat utility (short for Network Statistics) displays the current TCP/IP network connections and protocols information for the computer. The NetStat command symbolically displays the contents of various network-related data structures. There are a number of output formats, depending on the options for the information presented. For example, this command can be used to display a list of active sockets for each protocol being used. It can present the contents of other network data structures according to the option selected. The NetStat utility can also continuously display the information regarding packet traffic on the configured network interfaces.

Figure is a drag-and-drop activity that will help you in identify the command output your leaned earlier in this section.

Figure shows how trace route command works and Figure demonstrates how ping command works.