How should a user troubleshoot in case he/she is unable to use the internet ? List the steps in case of wired and wireless internet connections.
Answers
There are several areas that may be a cause of the problem.
The device itself e.g a Laptop,PS3
The local home network
The router
The connection to the ISP
DNS or DHCP
The Internet itself
Diagnosing the problem involves eliminating each of these possible areas in a systematic manner.
It is impossible to go though all possible scenarios, and so I will go through a connection problem scenario, and demonstrate how I personally would attempt to diagnose and fix the problem.
if you are new to networking I would recommend you read through the basic networking course before you start.
Before You Start -Eliminate the Obvious
Check that your router is plugged in and all cables to the router are secure.
The router will have lights, ensure that they are on and not indicating a problem.
If you are using a hub (wired or wireless) ensure it is plugged in and the cables are secure.
Problem 1 : Laptop Can’t Connect to the Internet.
Note: I use a windows computer but the process is the same on Linux and Mac
The first step is to have a clear idea of how the Laptop computer connects to the Internet under normal circumstances.
You may find sketching out a simple diagram helps
In my network my laptop computer connects to the wireless Router via wireless (secured) and the router connects to the telephone line and the ISP via a broadband filter.
The computer gets an IP address, and a DNS server Address from the router. Here is a quick network diagram of the arrangement:
Troubleshooting-network-diagram
First Checks:
Step 1. Is there a wireless connection between the computer and router?
Look at the wireless icon in the system tray. In my case if I hover the mouse over the icon a pop-up tells me the status.
As you can see below the signal strength is low, but I am connected, and to the correct network. (BT-HomeHub-0E2F).
troubleshoot-internet-connection-wireless
Note: the network name is important as you may have connected to a neighbours network by mistake.
Step 2. Check that you have a valid IP address by opening a command prompt, and using ipconfig/all command. (see below)
router-internet-setup-3
In the case above I have an address of 192.168.1.3 and a default gateway address has been assigned.
Therefore the computer connection to the wireless router is ok
If no IP address has been assigned then the IP address will be either:
0.0.0.0 or 169.254.x.y
The 169.254.x.y address range was introduced in windows 2000 and allows windows machines to automatically allocate themselves an IP address in the absence of a DHCP server.
If you see those addresses then you have a problem with the connection to the wireless router.
Step 3. We know that the computer-router connection is OK, so that leaves the router-internet connection to troubleshoot.
At this stage I will go to the router and examine the connection to the Internet to make sure none of the cables have been removed or come unplugged.
I also try to make a telephone call. If I get dial tone I know that the telephone connection is working, and it is not a cable fault.
My router has a collection of lights that indicate various conditions like Wireless functioning,Internet connected etc.
The manual that came with the router has more detailed troubleshooting tips.
However what I do now is to unplug the router from the mains power and leave it about 30 seconds to reset, and then plug it back in.
This has worked at least twenty times over the past 6 years.
If it doesn’t work straight away I leave it for an hour and repeat.
If it still doesn’t work then it is either a prolonged outage problem with the local ISP so I call the provider or it is a problem with the router.
You can eliminate the router by changing it with another working one (if you have one).
At this stage then if it isn’t working then you will usually require assistance from your ISP as they can do remote testing of your router, and the connection from the router to the ISP.
Answer:
These are just a few of the many common problems users ... Not being able to browse the Internet, intermittent connections ... I've covered many specific problems related to wireless