"CMD, cmd or cmd.exe, also known as Command Prompt, is the command-line interpreter in the OS/2, eComStation, Windows NT, Windows CE, and ReactOS operating systems.
It is the counterpart of COMMAND.COM in DOS and Windows 9x systems, and analogous to the Unix shells used on Unix-like systems." - Wikipedia
Welcome to the Command Prompt chapters and all the fun we will be having running commands to help us discover information.
Let's start this chapter with Ping, TraceRt and NSLookUp.
Ping is a computer network administration software utility used to test the reachability of a host on an network.
It is available for virtually all operating systems that have networking capability, including most embedded network administration software.
Type ping /? for help to get all of the options of the command. The most popular to me is the -t command that will continue until stopped.
It is great to use to see when a rebooted machine comes back up.
The IP address is listed along with the time it takes for round-trip time for the messages being sent.
Ping utilizes ICMP (Internet Control Message Protocol) type 8 which is an echo message and type 0 for echo reply.
TraceRoute and TraceRt are computer network diagnostic commands for displaying the route and measuring transit delays of packets across a network.
Type TraceRt /? for help to get all of the options for the command.
One or two asterisks for a hop does not indicate packet loss at the final endpoint.
Many routers discard ping or tracert which is called ICMP Rate Limiting which prevents routers from being impacted by denial of service attacks.
Request Time Out messages can be common and mostly ignored. The device might not respond to ICMP requests.
Request Time Out at the end of a tracert may appear as the destination firewall or other device is blocking the request.
NSLookUp is a network administration command-line tool available in many computer operating systems for querying the Domain Name System to obtain domain name or IP address mapping, or other DNS records.
Type NSLookUp /? for help to get all of the options for the command.
NSLookUp operates in interactive or non-interactive mode. Entering NSLookUp or adding - (minus) to the argument will enter interactive mode.
Entering NSLookUp <DOMAIN OR IP ADDRESS> will display non-interactive mode.
Adding -q=mx will find the mail server information for the domain or IP.
Ping, TraceRt and NSLookUp are great tools to use to find any possible networking issues.
We will continue to explore other Command Prompt options in the following chapters.
We have covered so far...
CH 1: CMD - Ping / TraceRt / NSLookUp
CH 2: CMD - IPConfig / NetStat / ARP