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configuration for our computer. And this information can




be used for problem-solving. So for example, if we open




up a command prompt and type in 'ipconfig /all', this




will display the full TCP/IP configuration for our




computer. Such as our computer name, MAC address,





IP address, default gateway - which is the router, DNS




servers, and so on.









































































The Ipconfig utility can be used to display the



full TCP/IP configuration for a computer.









By using this information we can find solutions if we are




experiencing problems. For example, if we had a




problem with our IP address, we can see from this




information that DHCP is enabled, which means that this




computer is getting its IP address from a DHCP server.





It also tells us the IP address of the DHCP server. It




also tells us the IP address of the DNS server. So if we




are experiencing any problems browsing the internet




with domain names, then there might be a problem with




the DNS server itself.







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Using the ipconfig utility by itself displays the IP address,




subnet mask, and default gateway. But using this utility




when combined with subcommands, called switches,




changes the output slightly. So for example, when we




use ipconfig /all, which we just used in our previous




illustration, displays the full TCP/IP configuration for our





computer. When we use ipconfig /renew, this releases




and renews the lease of the IP address given to us from




the DHCP server. And ipconfig /release, releases the




IP address, but does not renew it.









To see a complete list of all the switches that can be




used with ipconfig or any command utility, just type the




name of the utility along with a /? - and that'll show you




all the switches that are available for that specific utility.









Ipconfig /?







Example of a utility using a subcommand to display all




switches that are available.









Similar to the ipconfig utility that used in Windows, there




is also the ifconfig utility. The ifconfig utility is a





command that's used in Unix and Linux operating




systems. It displays configuration information from the




network interface card, such as the IP address, subnet




mask, how many packets it has received and sent, any




errors, and so on. And like ipconfig, it can also be




combined with switches to alter the output.










And our last utility is called nslookup. This name is




short for name server look up. And this utility is used to








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look up DNS information. So for example, at a




command prompt, if you type in nslookup, along with a




domain name such as yahoo.com, the result will give




you the information for the Yahoo domain. And the dig




command is the Unix version of nslookup. It does the





same thing.


































































Example of the nslookup utility























































































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