Nslookup (means name server lookup) is a network utility used to retrieve information about Internet servers.
As its name suggests, it finds information about the name server for domains by requesting a Domain Name System (DNS).
In addition to searching for server information, Nslookup can be used to test IP connections.
Users can receive data such as retry and timeout, assign a root server, or receive debugging information.
Nslookup can also be used to test mail exchangers or MX records that indicate the routing of e-mail messages according to which servers are connected to a specific domain.
The Nslookup tool allows you to retrieve information about both the host name and domain information. The domain is diagnosed and information is displayed on name servers, mail servers, Web and FTP servers.
Ping is a network diagnostic tool, used to test connectivity between two nodes or devices.
To ping the target node, an ICMP echo request packet is sent to this node.
If the connection is available, the destination node responds with an echo reply.
Ping calculates the travel time of the data packet from the source to the destination and vice versa and determines whether any packets were lost while driving.
The ping tool allows you to specify the number of times that packets are sent and the size of the packet.
Traceroute is a network diagnostics tool used to track the path, the packet passing through the IP network from source to destination.
Traceroute also records the time taken to pass each node (router) that passes the packet while traveling to the destination.
Traceroute uses Internet Protocol (ICMP) echo packets with a variable lifetime (TTL).
The response time of each node is calculated. To ensure accuracy, each response is requested several times (usually three times) to better measure the response of this particular node.
The Traceroute tool builds a table of passing packets to the target server. Choosing the option "Router info" will determine the physical location of the intermediate nodes (routers).
Whois is a tool that tells you the owner of any second-level domain name that registered it
Whois can also be used to see if a domain name is available or already occupied.
WHOIS services are mainly managed by domain name registrars and registries; for example, the Public Interest Registry (PIR) supports the .ORG registry and its associated WHOIS service.
The organization of ICANN coordinates a central registry for Internet resources, which includes a link to the WHOIS server of the responsible registry, as well as contact details of this registry.
The Whois tool determines the owner of the second-level domain, as well as the owners of computer subnets.