Ping and Traceroute

we have discussed about IP addresses , network basics in our previous post .if you have not read them read them first to get a better understanding.

LINK: https://iamafutureprogrammer.blogspot.com/2019/08/basics-of-network.html

What is ping ?

• It is a command in command prompt(windows).
• ping is used to test weather the destination is reachable by the source.
• Example:
• If I want to reach www.youtube.com then by using ping command we can find out weather we can reach the node or node.

Working is as follows,

• source send request messages to the destination computer,that request messages are called as ICMP (Internet Control Message Protocol).
• After sending request message the source waits for the response message from the destination.
• If the source receives the response message then it means that the destination is available otherwise its means that destination is not available.

You can try this command by,

• go to start -> type cmd -> click command prompt

now command prompt opens (make sure you have connected to internet before executing the command,if no internet connection it will say " host not available")

• type " ping(space)hostname ", host name can be www.google.com or www.facebook.com etc...
• note: enter the full address (not as facebook or facebook.com).

case 1: when the host you request is available  

• In the above picture we can see that we have made a request to youtube.com as " ping www.youtube.com " .we can also ping for any other host such as google.com,facebook.com etc...
• we can see 32 bytes of data is sent as request data.
• you can see 172.217.31.206 is the IP address of youtube and we get four reply messages (packets) from the host (here host is youtube.com)
• it also says the time taken to send reply in milli seconds and TTL stands for time to live .
• there is no loss since we got response for all the four packets we sent.

case 2  : when the host is not available or not internet connected

• In the above image you can see that we have requested for a host called www.gooooogleeee.com which is not a available host.so it says ping request could not find the host.

What is traceroute?

• traceroute is also a command used in command prompt.
• As we know that when a request is made from source (packet are sent) they travel through number of intermediate node(routers) to reach the destination .
• By using traceroute we can we the path and nodes through which the packets reaches the destination.

Using traceroute in windows,

1. go to start
2. type cmd and click on command prompt
3. command prompt opens(make sure you connected to internet)
4. type " tracert www.facebook.com" and hit enter.
5. Note: we use the command " traceroute " in mac and " tracert " in windows

Example:

• In the above example we have a tracert request to www.facebook.com
• 157.240.192.35 is the IP address of facebook as seen in the picture.
• It took 11 hops to reach the facebook.com (hops is the number of intermediate routers the packet is traversed through).

Note: there is not a single IP address for www.facebook.com or www.youtube.com the IP address may change based on the traffic.

If a particular facebook server has more traffic and i am requesting a facebook page at that time then the request goes to another facebook server with less traffic.

If you have any doubts ask in the comment section below.....Thank you....