What is an IP address and why am I trying to ping it?

That is an excellent question. I will be happy to assist you with IP addresses.

Well first off, IP stands for Internet Protocol and they deal mainly with Internet connections. So this is a term that alot of people use but most do not know what it is. I am sure you know that IP addresses are used by devices and websites to connect to the Internet, but how do they really work?

The short answer is that you have to think of an IP address as your home address. It is how the Internet is able to find your computer and vise versa. We think of a request from the computer to a website like sending a letter in the mail. Every connection and website has a unique address that allows traffic to know where to go. Basically, when you go to a website your computer sends out a request, “I want to find amazon.com”. That request is sent to a DNS (Domain Name System) server, which is basically a giant phone book that lists all websites and their IP addresses. The DNS server replies that Amazon.com is located at IP address 207.171.184.25 and your computer connects to it.

Now again this all happens in a fraction of a second. Another thing that people take for granted is just how complicated the Internet really is. IP addresses get a lot more complicated when you start boiling down exactly how your computer connects to the network. There are basically private and public IP addresses and  network translations but that is not really necessary for what we are trying to do here. Just understand that your router does most of the work and assigns the IP addresses to each device that connects to it.

setup-with-router1

So here are a few terms that are associated with IP addresses. The first and most common is DHCP (Dynamic Host Configuration Protocol) ,which simply means that the IP address you receive from the cable company is assigned automatically and has the possibility of changing. Dynamic just means changing.

The next is Static IP. This is mainly used by businesses or serious residential network nerds. Static IP is manually assigned and never changes. That is useful if you want to set up a web server for a website or an E-mail server. When you start directing traffic to something like that, you never want to have the IP address change or it could cause the whole thing to go down. This again is not something you would use at home for simple web browsing.

So lets move onto troubleshooting IP addresses. As an end user you will not being doing a lot of IP address troubleshooting. Most of the time if you are having an IP address issue it is because you lost Internet connection. When the service returns, the router will Dynamically reassign the IP address and you will be back online without really having to do anything.

If some of you want to dig a little deeper into the subject there are a few things you can do. The first is a ping test. You would do that from the command prompt on the computer and ping a specific web page like google. The ping test will send out a simple packet of data to the server and back. We measure how long a ping takes for a few reasons. First, if the ping never reaches the destination then the server is down and that is why we can not reach the website. Also we can test the speed of the internet by seeing how long it takes the packet to come back. We measure the round trip in milli-seconds and calculate the speed of the service.

In the example below, we see a ping test to Youtube.com which gets translated to Youtube’s IP address. Then four packets are sent to that address. Bytes means the size of the packet sent. Time is the round trip in milli-seconds and TTL means time to live which is how long the packet will attempt to make the connection before it gives up. So the results are four packets sent, four received, with no packets dropped, which means that Youtube is up and running with no issues.

Cmd-ping

The next thing is called a trace route. A trace route is another small packet of data that you send to a specific website. The difference is that a trace route tells you all the different connections it had to go through to get to the destination site. This is useful if you are having an issue getting to a specific website but the site itself is not down. This will show you where the packet is dying and what part of the connection is having trouble. This again is not something the normal user will ever do but if you want to see how many routers and connections a request goes through, it is a fun experiment.

So again, in the example below we see that some one tried to trace the route from their computer to mediacollege.com. The packet is sent out and reports back all the connections it uses to get to that website. Each time the packet changes connections that is called a hop. So this packet used 19 Hops to get to it’s destination. So if there was a network issue somewhere on the connection the packet would start returning a request timed out error and stop returning server information. That tells you where the connection is dropping and allows you to pin point what needs to be fixed.

traceroute

Now this information is presented simply as a “thought” experiment trying to show that the internet connections that happen so quickly do have many moving parts. Again, this is not something you would mess with in normal internet troubleshooting ,this is next level specific troubleshooting that most people will never deal with.

If you have a technology question would like answered please E-mail speakslowerblog@gmail.com and I will be happy to look into for you.

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