Name Resolution and nslookup:
Name Resolution:
- Name resolution is the process of converting human-readable domain names (like google.com) into IP addresses that computers use to locate each other on the network.
- The operating system usually handles name resolution, but as an IT support specialist, you may need to use command-line tools to troubleshoot DNS issues.
nslookup:
- nslookup is a command-line tool available on Linux, macOS, and Windows for querying DNS records.
- It allows you to manually perform DNS lookups and understand the name resolution process.
Basic Usage:
- A basic usage of nslookup involves providing the hostname as an argument to the command.
- For example,
nslookup twitter.com would return the IP address associated with twitter.com.
Interactive Mode:
- Nslookup also offers an interactive mode for more advanced queries and configurations.
- Enter
nslookup without a hostname to start an interactive session (indicated by the angle bracket prompt).
Interactive Mode Options:
- server: You can set a specific DNS server to be used for subsequent queries by typing
server followed by the server's IP address.
- set type: You can specify the resource record type you want to query (e.g., A, MX, TXT) using
set type=record_type.
- set debug: Enables debug mode, showing detailed response packets and information like TTL, serial number, etc.
Usage Note:
- Nslookup is a powerful tool that offers more capabilities than covered here.
- Exploring its interactive mode and options can help troubleshoot DNS-related issues effectively.