1. Ping
Hackathon
2018

2. Pinging Ping is short for Packet Internet Groper
It is a utility that sends a message to a computer and waits for a response
A utility is part of system software that is used to help manage the computer’s resources, as opposed to application software
If the response is received, information about the times required and so on are reported
If the response is not received in a certain amount of time, the request is said to have “timed out”

3. Pinging (Cont.)
It works by sending special packets called ICMP (Internet Control Message Protocol--echo request and echo reply packets) to a destination which is defined by an IP address or URL. (We will learn more about ICMPs later in the semester.)
If the destination responds, you have a good connection and a working route.
If the destination does not respond, you really can’t determine anything about the connection. Many computers turn off the ability to use this service.

4. Breaking it down
Pinging consists of the command “ping” followed by an IP address or domain name
ping
ping
It sends out special packets which request a response (echo reply) if the destination host is reached

5. host
A host is a computer or device that is connected to a TCP/IP network, including the Internet.
Each host has a unique IP address.
A computer may always have the same address or may have a different address each time it connects to the networks.
For wireless networks, the IP address may easily change.
IP addresses should be unique.

6. Domain name
A domain name is a string of characters standing in for an IP address
You can have
One Name which links to Multiple Addresses
One Address which links to Multiple Names
Domain names are used in URLs to identify particular Web pages. For example, in the URL the domain name is pcwebopedia.com.

7. Packet
The information that moves between computers is a called a packet. Packets hold all the information.
So, a packet is a message (protocol + “some” data) or a piece of a message transmitted over a packet-switching network.
Packets contain an address (identifier) so that it can be routed to its destination.

8. Now we are going to try some pinging exercises.
You are going to use the command line for your computer. The next set of slides will show you how to get this information.
Go to the start command and in the search box type cmd. (next slide).

9. Pinging: Start/Run

10. Type cmd in the search box
Type cmd here and click on the x

11. Pinging: type ping followed by domain name

12. You will get a black window where we will issue commands.

13. Pinging
You are going to look at some examples and then try this on your own machine.

14. Pinging a host which was off at the time
Timed out
Can use IP instead of domain name

15. Traceroute
Hackathon
2018

16. Traceroute
This is a utility that determines the route taken by a packet from your computer (the local host) to some other host on the network
It doesn’t actually follow a single packet but sends out a series of packets
The packets are restricted in the number of “hops” they can take
When the limit is reached, information about the node is (should be) returned
Each consecutive packet is allowed one more hop

17. hop
A hop is a term that describes when a packet moves from one from one node to the next.
“Some Internet Service Providers (ISPs) advertise how many hops away from Internet backbone they are. Theoretically, the fewer hops it takes to get your data onto the backbone, the faster your access will be.” (webopedia)

18. Traceroute (Cont.)
Traceroute shows how many hops were required to reach the destination as well as the length of time for each hop.
You can use traceroute to get an idea of where things move through the internet.
This can be useful in trying to determine how information passes through the connections.

19. Traceroute (Cont.)
Go to Start/Run, type cmd, and then type “tracert” followed by the domain name of the host.
For example:
tracert

20. tracert google.com