We’re getting to mention one among the foremost widely used utilities that are utilized in networking, and i am talking about the Ping command.
What Is Ping?
Now the ping command may be a simple tool that you simply can use to troubleshoot networking issues, like network connectivity. So you’ll use it to check if you’re connected to a local area network or if you’re even connected to the internet. you’ll also use it to check if your network interface card is functioning correctly and it is also used to test DNS issues, like name resolution. So for example, let’s go ahead and ping an IP address of a host. Now, this host might be any network device, like a computer, server, router, or printer, whether it’s on your local area network or over the internet. But in this example, we’re getting to ping a server in our local area network. So we might open up a prompt then we might type the word ping alongside the IP address of the server then press ‘enter’. Then the ping utility will send 4 data packets to the IP address of the server, then our computer will await a response. Then the server will send the data packets back to us as a reply and these replies are called echo reply requests and these replies inform you about what’s happening with the server we pinged.
For example, if we received a reply then that’s a good sign. Then that means that there’s network connectivity between us and therefore the server, whether that server is on your local area network or over the internet. So 4 packets were sent then 4 packets were received. But if we ping an equivalent server and this time if we didn’t get a reply, then meaning that the server didn’t reply back and it could mean that there’s no network connectivity between our computer and therefore the server. Now, this might be for several different reasons. So for instance , once we ping the server and if we get a message back that says ‘request timed out’ then that would mean that the server is powered down or it could also mean that the server is up and running but it’s using a firewall that’s blocking all ping requests.
Now, what happens once you attempt to ping a host and not all of the data packets reply back to you? So once you ping a number, your computer sends out 4 data packets. But sometimes you’ll only get 1, 2, or 3 packets back rather than the 4 that you simply sent out. Well, this is often called packet loss and packet loss can occur for several reasons. It could mean that there is network congestion. If there is tons of traffic on a network and therefore the network can’t handle all that extra traffic, then the data packets will get dropped. Or it could also happen due to faulty hardware, like bad cables or bad wiring. Or it might be a nasty network card or bad connections, or it could be a bad modem,
if we wanted to ping a foreign server on the web and if we got a message that says ‘destination host unreachable’ then meaning that a route to the destination can’t be found. So it could mean that a router doesn’t have any information on the way to route data to the destination or it could also mean that the remote server is down or disconnected from the network. Or it could also mean that your computer isn’t connected to a network.
So let’s use the ping command during a typical scenario. So suppose someone tells me that they do not have an online connection because they can not access any sites with their computer, which may be a pretty common issue. therefore the very first thing I do is I might sit at their computer and use the ping utility to see if actually they’re not connected to the internet. So even before I check their modem, or router, or any cable connections, the first thing I do is do an easy ping test. So I might open up a command prompt and see if I can ping a website, like yahoo.com. Now notice during this method I’m actually pinging the name yahoo.com and not its IP address. Because by doing it this way, I’m also testing name resolution issues associated with DNS, and also besides that, i do not have yahoo’s IP address memorized. So by pinging yahoo.com, and if the ping is successful, then I do know that we are connected to the web because once I got a successful reply from yahoo.com. Then I automatically know that all of my hardware, like my cables, the network card, the router, and therefore the modem, are all working correctly, including my internet service provider.
So now i know that the reason that this computer can’t bring up web pages is related to software and not hardware. so the problem is presumably with their internet browser or it is a firewall issue.
So by doing a ping test first, it saved me tons of time because I bypassed the effort of looking around for the modem, or the router, or looking at LEDs, or checking the cables, or looking behind the pc to ascertain if a network cable is plugged into my network card