Ping Hackathon 2018

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”

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.

Breaking it down Pinging consists of the command “ping” followed by an IP address or domain name ping 139.84.10.210 ping www.lasalle.edu It sends out special packets which request a response (echo reply) if the destination host is reached

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.

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 http://www.pcwebopedia.com/index.html, the domain name is pcwebopedia.com.

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.

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).

Pinging: Start/Run

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

Pinging: type ping followed by domain name

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

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

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

Traceroute Hackathon 2018

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

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)

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.

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

tracert google.com