Type the command ipconfig displaydns.

Implementing TCPIP in the Command Line | 105 As you can see, the ipconfig command has many uses. It can be used to analyze and troubleshoot basic networking connections, as well as to troubleshoot DHCP and DNS issues. Let’s move on to the ping command. Ping is used to test the existence of other hosts on the network. However, there are many permutations of ping. 7. Type the command ping ?. This displays the help file for the command. Note the various options available to you.

8. Ping the local host computer and other computers on the network:

a. Type the command ping localhost.

b. Type the command ping loopback.

c. Type the command ping 127.0.0.1.

The first two commands are basically the same. However, when you ping 127.0.0.1, the results do not include any hostname resolution information. This is the best way to ping the localhost when testing IPv4. When pinging 127.0.0.1, no traffic is placed on the network segment; rather, all traffic is kept inside the computer or local loopback. Now select another computer to ping; it could be a partner’s computer, a secondary computer, or a router. Make note of its IP address. For this example, we will use the address 10.254.254.252. d. Type the command ping [IP address]. For example ping 10.254.254.252. This tests whether another host on the network is live. You can also ping another computer on the network by host name. To find out the host name of a computer, type either the command hostname or the command ipconfig. Examples of pinging an IP address and pinging the corresponding host name are shown in Figure 5-8. Notice the IP address in the first ping 10.254.254.252, as well as the host name server2003 and resolved IP address 10.254.254.252 in the second ping. Disable IPv6 in the Local Area Connection Properties window before continuing with this portion of the exercise. If you get replies that include::1 in the address, then IPv6 is still functioning. TAKE NOTE Figure 5-8 Pinging by IP address and host name If the computer you pinged is alive, the pinging computer will get replies. However, if the computer is not live or is not available, you will get one of several error messages e.g., “Request timed out,” “Destination host unreachable,” or a similar error. When troubleshooting network connectivity issues, start with the local computer and then branch out. For example, start with a ping of 127.0.0.1, then try pinging