Networking tools

Networking tools are small programs that test connections, look up information and diagnose faults on computer networks and the internet. They work by sending standard requests and interpreting the replies, which makes the otherwise invisible behaviour of a network observable. Many of these utilities are command-line classics that have been part of operating systems for decades, while others are graphical or run inside a web browser, and a large number are freely available.

Several tools test whether a remote machine can be reached and how. Ping sends a small probe and waits for a reply, reporting whether the host responds and how long the round trip takes. Traceroute maps the path packets follow, listing each intermediate router, or hop, between the local computer and the destination, which helps locate where a connection slows down or fails. These two tools together answer most basic questions about reachability and routing.

Other tools reveal information about names and addresses. DNS lookup utilities translate between human-readable host names and the numeric IP addresses computers actually use, and can query specific record types. Whois queries the public registries that record who is responsible for a domain name or block of addresses. The older finger protocol could report on users of a remote system. An IP subnet calculator works out network and broadcast addresses, ranges and masks from an address and prefix, helping plan how an address space is divided. Together these tools form a basic toolkit for understanding and troubleshooting networks.

Frequently asked questions

What is the difference between ping and traceroute?

Ping checks whether a host responds and measures the round-trip time. Traceroute lists every router along the path to that host, helping show where a problem occurs.

What does a DNS lookup do?

It translates between host names, such as a website address, and the numeric IP addresses computers use to find each other on the network.

What is an IP subnet calculator for?

It computes the network range, mask, and broadcast and host addresses for a given IP address and prefix, making it easier to divide an address space into subnets.