CertiGuide to A+ (A+ 4 Real)  9  Chapter 14: Networks       9  What is a Network?            9  Network Utilities

IPCONFIG and WINIPCFG 1 Dial Up Networking

NSLOOKUP is a simple tool that provides an interface for querying a DNS server’s information; as discussed previously a DNS server holds information to translate IP addresses to human friendly names, and vice versa. The distinction here is important – NSLOOKUP does not perform this translation itself, it simply provides a method of communicating with a DNS server. Whilst the tool itself is simple, querying a DNS server using it allows for extremely complex use that is outside the scope of the book. This section will cover the most common basic uses of the tool.

NSLOOKUP has 2 modes of operation. The first is a simple command prompt query to resolve a name either to an IP address, or vice versa. The syntax of the command is NSLOOKUP <IP address or name>, as shown in Figure 447.

Figure 439: NSLOOKUP command of an IP address

The second mode is an “interactive mode”, which provides a full interface to a DNS server to perform queries. To access this mode, type the NSLOOKUP command at a command prompt with no parameters. You are presented with the interface of Figure 448.

The single “>” indicates you are in the NSLOOKUP interface. As you can see, you are able to translate friendly names to IP addresses and vice versa without prefixing each line with the NSLOOKUP command. Typing “exit” at the prompt will return you to the command prompt.

IPCONFIG and WINIPCFG 1 Dial Up Networking