TROUBLESHOOTING NETWORK CONNECTIONS 
 
Summary 
 
Networking has seen a huge gain in popularity over the last several years. 
Prices for networking equipment have dropped, a whole slew of network products 
are available for both business and home networking, the majority of new PCs and 
laptops come equipped with network adapters right out of the box, and setup has 
become much easier. As a result, many computers are connected to office and/or 
home networks, both wired and wireless. 
 
As easy as it can be to set up a new network, networks can be complex and 
involve many parameters and components that can easily be misconfigured or fail. 
Troubleshooting a broken network connection can be a daunting task for the 
average user. Following instructions to set up a basic network from scratch is 
one thing - finding a problem is a whole different story.  
 
This article covers a number of typical scenarios of a PC connected to a network 
and offers a list of logical and straight forward troubleshooting steps for each 
specific scenario to make the troubleshooting process easier and take some of 
the scariness out of it. 
 
The instructions and troubleshooting steps found in this article are mainly 
geared towards computers running Windows 2000 or XP as they are currently the 
most common Windows operating systems connected to networks. While Windows 9x/ME 
can also be connected to a network, they are outdated versions of Windows and 
can be a pain in the butt to get to work on a network. However, even though the 
examples given are usually Win2K / XP commands, they either will work in other 
operating systems or have similar equivalent commands. Additionally, most of the 
troubleshooting steps are generic enough that they apply to other operating 
systems as well.  
 
When the instructions refer to checking a setting or configuration parameter for 
a certain piece of hardware such as a gateway device, they are purposely generic 
as every device is different. It is up to you to consult the manual and figure 
out how to get to the appropriate menu option or section. 
 
Contents 
 
- Summary, Networking Basics  
- Troubleshooting Essentials  
- Troubleshooting connection and configuration  
- Accessing network resources  
- Gateway configuration  
- Gateway firewall  
- Log files  
- Hardware failure  
- Conclusion  
 
Networking Basics 
 
Before delving into the troubleshooting process, it is important to understand 
the basic concept of networking. The purpose of connecting a PC to a network is 
to exchange data with another PC such as sending an email, viewing a web page, 
or copying a file. The other PC can be physically close such as in the same room 
(home network) or the same building (office network), or physically remote such 
as a web server in a different state or country. The Internet is nothing but a 
gigantic network of countless computers, all interconnected via a myriad of 
hubs, switches, routers, and firewalls. By connecting your PC to a DSL or cable  
modem or plugging into an office network you get access to this network and the 
ability to exchange data with a number of other machines that are on that 
network. 
 
To participate in a network, a PC requires the following components: 
 
- Operating system (or short OS) - Pretty obvious. Without an operating system  
installed such as Windows or Linux, the PC isn't good for much. 
 
- Network application - to participate in a network you need a program that can 
send and receive data over the network. This could be a web browser, an email 
program, an FTP client, a Telnet client, a game with multi-player capabilities 
such as Half-life or Quake, or a chat program such as Yahoo or IRC, just to name 
a few. 
 
- Network protocol - All operating systems usually automatically install a 
networking protocol, normally TCP/IP which is the most common network protocol. 
There are others such as IPX/SPX, but TCP/IP is by far the most popular one as 
the entire Internet and the vast majority of all home and office networks are 
based on it. 
 
- Network configuration - Every computer that wants to participate in a network,  
requires a number of pieces of information. Most importantly, it needs an 
address so it can be uniquely identified on the network. This is just like 
everybody with a telephone having a unique phone number. This address is called 
an IP address and could look like this: 10.0.2.25. It also needs a subnet mask 
which indicates the size of the network, the network number, and its broadcast 
address. It could look like this: 255.255.0.0. Then it needs the IP address for 
the gateway. This identifies the computer on the network that passes data back 
and forth between the network the PC is on and the next network segment. These 
are the absolute minimum configuration requirements to successfully configure 
TCP/IP for network connectivity. 
 
- Network adapter - Also known as network interface card (or short NIC) or 
ethernet adapter / card. This can be a PCI card inserted in the motherboard of a 
PC, a PCMCIA card inserted into a laptop, or an external adapter connected via 
USB. The network adapter can be either for a wired or a wireless network. 
 
- Driver - No matter which type of network adapter is used, it has to have a 
driver installed in the operating system. A driver is a small piece of software 
specific for each OS that is provided by the manufacturer of the adapter. It 
contains instructions and information that allow the OS to communicate with the 
network adapter and pass data and instructions back and forth. Depending on the 
OS and the type of adapter, the driver may be already provided and automatically 
installed. If not, it needs to be manually installed. 
 
- Network cable - If the adapter is for a wired network, a cable is required to 
physically connect the network adapter to a network jack in a wall, hub, switch, 
router, etc. A network cable is also often referred to as a Cat 5 cable, short 
for Category 5 which is currently the most common type of network cable. There 
are two main types of Cat 5 cable: straight-through and cross-over. This refers 
to the way the 2 of the 4 wire pairs inside a Cat 5 cable that transmit the data 
are arranged on each end. More details about this can be found in the Cat 5 Do-
it-yourself article. 
 
- A functional network - Of course a working network is required to connect the 
network cable to. This can be a corporate network in the office, a small home 
network, or the Internet directly via a broadband connection such as DSL or 
cable modem. This network consists of more cables, hubs, routers, switches, etc. 
that all have to be configured and function properly for your data to be able to 
reach its destination and the reply to return to you.  
 
In a simplified manner, here's how a data transmission over a network functions. 
When an application wants to communicate over the network, it cannot access the 
network directly. It has to format its request according to the rules set by a 
protocol and pass it down. The request will be handled by several layers which 
are known as the 7 layers of the OSI model. Each layer will wrap and tag the 
data package and pass it on to the next until it is finally placed by the 
network card in form of an electrical signal on the actual wire and transported 
to the next stop on the way. The packet has to pass a number of "hops", which 
are routers that redirect it along the way to help reach its target. Depending 
on the location of the target, this could be just one or two hops if it's on the 
same network, or 20 - 30 hops if it is far away in a different state or country. 
At the final destination the packet is passed through all 7 layers, this time in 
reverse order, and finally ends up at the recipient. Here the request gets  
processed, the reply will be packaged and passed through all layers to be sent 
back to the originator. 
 
This whole process is pretty complex and could take a book to explain, which is 
beyond the scope of this article. The point of this summary is to present an 
idea of how many devices and wires the data has to travel to reach its 
destination. Given the complexity of networking and the vast amount of 
components and parameters involved, it's quite amazing that everything works 
together so well, enabling us to send and receive data from around the globe in 
a matter of seconds. However, once something breaks, this complexity comes back 
to bite us in the butt because there are so many things to check when 
troubleshooting a network connectivity problem. 
 
The only way to successfully troubleshoot is by following these four important 
steps: 
 
- Stay calm and focused - While the initial reaction to an unexpected network 
problem may be "Oh crap!", panicking won't solve anything. A clear head and 
focus is essential to successful troubleshooting. 
 
- Understand the exact scenario at hand - In order to fix something, you have to  
understand how it works, what components are involved, and how they work 
together. This knowledge is half the solution to the problem. 
 
- Be methodical and logical - Randomly poking around and changing things will 
make the problem only worse, not better. The best approach is to make a list of 
possible problem areas and then handle each item one step at a time: Make one 
correction, test whether it fixed the issue. If not, set it back the way it was, 
then move on to the next item. 
 
- Be thorough and don't make assumptions - Check every single component, leave  
nothing out. Don't assume it's not the network card because it was working 
yesterday. Maybe the computer got bumped and the network card became unseated 
from its slot. Don't assume it's not the cable because it's brand-new. Maybe 
your kid's pet rabbit chewed on it. You see where this is going. There are 
always unforseen circumstances beyond your knowledge that could be causing the 
problem. Make sure you check everything. 
 
Armed with this knowledge, it's time to move on to the actual troubleshooting 
process. Below are four common situations how a PC can be connected to a 
network. Pick the one that closest resembles your network, then proceed to the 
troubleshooting section. The majority of the steps are applicable to all four 
scenarios, but some of them vary depending on the network setup. In this case, 
the steps will refer separately to each setup. It is essential that you can  
identify the correct network setup and understand how the components are 
connected in order to successfully troubleshoot the problem. 
 
Scenario 1: PC -> DSL or cable modem 
  
Scenario 2: PC -> gateway device -> DSL or cable modem 
  
Scenario 3: PC -> Hub/switch -> Gateway device -> DSL or cable modem 
  
Scenario 4: PC -> company network 
  
Check the physical connection at the computer - Verify that the network cable is  
plugged in securely into the network card in the computer. Unplug and re-plug it 
to be sure it is plugged in tight and correctly. If this is a laptop using a 
PCMCIA card with a dongle, verify that the cable is connected to the dongle and 
that the dongle itself is connected securely to the network card. If the 
computer has multiple network cards, verify that the cable is plugged into the 
correct one. 
 
Check for a damaged or misconfigured cable - While checking the physical  
connection, examine the network plug on each end of the cable as well as the 
jacks they plug into. Make sure there are no bent or missing pins. Don't forget 
to try another cable to make sure the current one is not damaged. Excessive 
force such as sharp bends, knots or kinks can damage the wires inside the cable. 
As mentioned previously, depending on what devices are connected either a 
straight-through or a cross-over cable is required. A straight-through cable  
works for most situations though. 
 
Check the physical connection at the other end - Verify that the cable is 
plugged securely into the network port/hub/modem/walljack on the other end. If 
plugged into a hub or switch, check whether the link light is on. If the link 
light is not lit, it could indicate a bad/incorrect cable or a bad port. Try a 
different port on the hub or switch. Another thing to check with a hub or switch 
setup is to verify that the connection from the hub or switch to the next hop 
such as the gateway device or cable/DSL modem is working by checking the link  
light on both ends of the connection. If connecting to an office network, make 
sure the cable is plugged into the correct port. For example, there may be 
several ports, one for data, one for voice. Verify with the IT department that 
the data jack has been activated and is connected to the local network.  
 
Check the hardware for proper installation - If the network card is a PCMCIA 
card, verify it is inserted all the way into the correct slot. If it is a PCI 
card, verify it is seated properly in its PCI slot. If it is an onboard network 
adapter (built into the motherboard), verify that it is enabled via a jumper on 
the motherboard or a setting in the System BIOS. Make sure the network card is 
installed properly in the operating system. In Windows, check Device Manager for 
presence of the network adapter and verify that there are no conflicts or 
errors. To ensure there is no problem with the driver, download and install the 
latest driver from the manufacturer's website. 
 
Check the PC network configuration - In order to participate in a network, a 
network protocol has to be installed and configured properly. As mentioned 
above, the most common protocol is TCP/IP which is installed automatically by 
most operating systems. There are two ways to configure TCP/IP: Static or 
dynamic. Dynamic means that when the machine is connected to a network it will 
send a broadcast asking for configuration information. If there is a DHCP server 
on the network that observes the request, it will reply and send the machine the 
required information such as IP address, subnet mask, gateway IP address, and 
DNS server IP. In this case TCP/IP just needs to be set to obtain an IP address 
automatically (default configuration in Windows), no other configuration 
required. This configuration type is very convenient because it does not require 
any changes on the computer when the network configuration changes or when it is 
connected to a different network. Static on the other hand means that the user 
has to supply and manually enter this information into the TCP/IP configuration. 
Without the proper information the computer cannot participate in the network. 
 
Scenario 1 - PC -> DSL/Cable modem: Check with the ISP to find out whether they 
use dynamic or static IP configuration. Most DSL and cable modem plans use 
dynamic mode, therefore it's best to try DHCP first. 
 
Scenario 2 - PC -> Gateway device: Here it depends how the gateway device is 
configured. Again, the typical setup is DHCP enabled for automatic 
configuration, so try this option first, unless you have specifically turned 
DHCP off when you set up the gateway device. 
 
Scenario 3 - PC -> Hub/switch -> Gateway device -> DSL or cable modem: See steps  
for scenario 1 and 2. 
 
Scenario 4 - PC -> Office network: Contact the network administrator to find out 
whether the network uses dynamic or static IP addressing. Once again, DHCP is 
the most common configuration, so try that first unless the network 
administrator tells you specifically to use a certain static IP configuration. 
 
If TCP/IP is configured for DHCP, there is an easy way to check whether it has 
received proper IP configuration information. Open a command prompt by selecting 
Start / Run, typing cmd, and pressing Enter. Type ipconfig or ipconfig /all to 
get more detailed information and press Enter. 
 
The same information can be accessed in Windows from the network connection 
panel by right-clicking on a connection and selecting Status. While at the 
command prompt, run the command ping 127.0.0.1. This is the loopback address and 
tells the PC to send a packet to itself. It is a simple test to ensure that the 
TCP/IP stack is working properly on this machine. If this fails, you may have to 
repair or reinstall TCP/IP. Next, try pinging the IP address of the PC itself 
(the one you just looked up using the ipconfig command) to make sure the network 
card is working properly. If this fails, remove the network card drivers and 
reinstall it. 
 
Check for firewall software - Find out if the machine is running any firewall 
software such as Zone Alarm. If misconfigured, it could prevent the computer 
from requesting or receiving DHCP configuration. If firewall software is 
running, turn it off temporarily while troubleshooting to eliminate it from the 
list of possible causes for the failure. If the connection works correctly as 
soon as you disable the firewall software and breaks again as soon as you  
reenable it, you found your culprit. Check its configuration and correct any 
firewall or program rules that may be blocking the connection. 
 
Check connectivity to the next hop - When information is transported on a 
network, it is being handed from one station to the next like in a relay. If any 
of the stops along the way is broken or doesn't know where to relay the 
information to next, the entire chain breaks down. Therefore it is very 
important to methodically check the chain and identify where exactly the 
breakdown occurs. The illustration shows the hops for this particular setup. The  
ping and tracert commands are two simple but effective tools to check for such 
breakdowns. The ping command sends a number of test packets to the IP address or 
host specified and displays whether it received a reply and how long it took. If 
there was no reply, you know that the destination could not be reached. The 
tracert command is similar but it also documents all stops between the computer 
it is run on and the destination with times between hops. It will show where 
there may be a long delay or a complete breakdown along the way so you know  
where to focus your troubleshooting. 
 
Run the ipconfig /all command to find out the PC's IP address and the gateway 
IP. Look at the gateway configuration to find out the ISP's router IP address 
your gateway device points to. Now systematically ping every single hop by 
running ping (IP address) beginning with the one closest to your PC which is the 
default gateway. If you get a reply, ping the next one and so on until you have 
found one you can't reach, indicating the possible point of failure. 
 
Caveat: You have to take the ping results with a grain of salt. A failed ping 
does not necessarily mean a broken hop. It could just be a switch, router, or 
firewall that is configured to drop ICMP packets (which includes ping). If a 
traceroute to the destination goes past the device that doesn't respond to ping, 
it's probably not the point of failure you're looking for. 
 
Check DNS settings - If the network configuration checks out, but the problem is 
that you still cannot view any websites in your browser, the problem may be with 
the DNS settings. DNS stands for Domain Name Service which is the mechanism that 
translates a website address (URL) into the actual IP address of the webserver 
it resides on. When you type a URL into the address bar of your browser, it 
first makes a request to the ISP's DNS server to find out what the IP address 
for that particular website is. Once it knows the IP address, it then sends the 
actual page request to that server. If no DNS server is available, the name 
lookup fails and it cannot access the website. Test this from a command prompt 
by typing nslookup pcnineoneone.com for example. If DNS is working properly, you 
will see the IP address displayed. If it fails you will see an error message. 
Alternatively, if you happen to know the IP address for a website, type it into 
the browser's address bar instead of the URL and see if that pulls up the site 
correctly. 
 
Run ipconfig /all and check for the existence of at least one DNS server IP 
address. If there is no DNS server listed, run ipconfig /renew. If that does not 
obtain the proper information, the resolution depends on the TCP/IP 
configuration. If configured for DHCP / dynamic IP addressing, the DNS server 
should have been provided by the DHCP server together with the IP address and 
gateway.  
 
Scenario 1 - PC -> DSL/Cable modem: Contact the ISP for help. 
 
Scenario 2 - PC -> Gateway device: Log into the gateway device and check if it 
received the proper DNS server information from the ISP, as well as whether it 
is configured to pass it on to the clients on the network via DHCP.  
 
Scenario 3 - PC -> Hub/switch -> Gateway device -> DSL or cable modem: See  
scenario 2. 
 
Scenario 4 - PC -> Office network: Check with the network administrator to have 
the DHCP server settings checked. 
 
If configured with static IP information, check the TCP/IP settings and make 
sure that at least one valid DNS server IP address is entered. It is normal to 
have two or three DNS server addresses listed to have a backup in case a DNS 
server becomes unavailable. 
 
IP address conflict - It is possible to receive an error message that there is 
an IP address conflict due to another host with the same IP address present on 
the same network. This usually happens when two PCs are manually configured with 
the same static IP address.  
 
Scenario 1 - PC -> DSL/Cable modem: Check to make sure you entered the correct 
IP configuration as provided by the ISP. If that does not help, contact the ISP 
for further assistance. 
 
Scenario 2 - PC -> Gateway device: Check all PCs on the network and verify that 
they all have unique IP addresses. 
 
Scenario 3 - PC -> Hub/switch -> Gateway device -> DSL or cable modem: See  
scenario 2. 
 
Scenario 4 - PC -> Office network: Contact the network administrator for help. 
 
Tip: There is an easy way in Windows XP to "repair" a network connection. 
Navigate to Start / Control Panel / Network connections / Right-click the 
problematic connection / Repair, or double-click on the network connection icon 
in the system tray if present and select Support / Repair. This performs the 
following actions to attempt restoring the network connection: It broadcasts a 
DHCP request, flushes the local ARP (Address Resolution Protocol), NetBIOS, and 
DNS cache, and reregisters with WINS (Windows Internet Name Service) and DNS. If 
it encounters an error in the process it will display it on the screen when  
it's done, providing a potential clue. 
 
MAC address conflict - A MAC (media access control) address is a unique 
identification number that is assigned to each network adapter and is used to 
route network packets between nodes on a network. It uses the hexadecimal format 
and could look like this: 00-90-4B-B2-1A-86. ipconfig /all will list the MAC 
address for the network adapters in a computer. Any manufacturer of network 
adapters hardcodes a MAC address in each adapter, drawing from a range of 
addresses assigned to them. The first half of the MAC address identifies the 
manufacturer of the adapter, the second half uniquely identifies the adapter. It 
is extremely unlikely but theoretically possible that two devices on a network 
have an network adapter with the same MAC address. Because this scenario is so 
rare and requires advanced troubleshooting it is beyond the scope of this 
article. 
 
Check for required authentication - On a corporate network network access may  
require additional authentication. e.g. a certificate, VPN, RADIUS, EAP, etc. It 
may also have MAC filtering, allowing only computers on the network whose MAC 
address is on a list of approved nodes. 
 
Wireless network configuration - Troubleshooting a connection to a wireless 
network involves a few additional parameters to check against the configuration 
of the wireless access point. Each wireless network has a network name or SSID 
(Service Set Identifier). Check the properties for the wireless network 
configuration and verify it has the correct SSID entered. Wireless networks, 
when properly configured and secured, usually use encryption. Check whether the 
wireless network you're connecting to uses encryption and if so, ensure you have  
the correct encryption key entered. Wireless networks also may be restricted to 
only accept connections from computers with an approved MAC address. Check 
whether this is the case and if so, whether the MAC address of your computer is 
on the access list. 
  
Accessing network resources 
 
A common scenario of network problems is trying to access resources on a 
different computer over the network, e.g. copying files from a laptop to a 
desktop machine, backing up folders to a hard drive on another computer, sharing 
photos or music stored on one computer with other computers on the network etc. 
The following is a list of most common configuration problems. 
 
Check the Workgroup - On each machine, right-click on My Computer, select 
Properties and make a note of the workgroup. In order to see each other in a 
peer-to-peer network, all computers must be in the same workgroup. Change all 
computers to the same workgroup, reboot, and try again. This does not apply to a 
domain-based network. 
 
Check File and Printer Sharing - Check the network connection properties and 
verify that File and Printer Sharing is installed. If not, add it and reboot. 
 
Supply the proper authentication - Depending on how the resource you want to 
access is set up, you may have to authenticate yourself first to the other 
computer. If you receive a dialog box asking for authentication when trying to 
access a share on another computer in Windows Explorer, enter the computer name 
you wish to access, a backslash (\), a username from that computer, and then the 
appropriate password in the password field. 
 
Example: You are working on a computer called HomePC1. You are logged in as user 
MaryG. This user account exists only on the computer HomePC1 and is therefore 
called a local account. 
 
You are using Windows Explorer to browse the network neighborhood to a computer 
called HomePC2 to access files on a share called Documents on that machine. You 
find the computer and that share, but when you click on it, you get prompted for 
authentication. The reason for this is that apparently the share does not allow 
access to anybody, but only to qualified users. It prompted your PC for 
authentication information and it replied with the account you're logged in as, 
MaryG. Since that did not match, it asks you now for another user account. 
 
You have a user account on the computer HomePC2 called JackS with the password 
12345. To authenticate, you type HomePC2\JackS in the username field and 12345 
in the password field. After pressing Enter, you are able to access the share 
now since JackS has rights to access it. 
 
Alternatively, you can also use a command-line to map a network drive to the 
desired share on that computer. Open a command prompt and type the following 
command: 
 
net use * \\HomePC2\Documents /user:HomePC2\JackS 12345 
 
This will map the next available drive letter to the share Documents on the PC 
called HomePC2 and use the account JackS with the password 12345 as 
authentication. Windows Explorer will now show a new drive letter that points 
directly to that share. 
 
In a more advanced office network there will be a domain. A domain means 
managing user accounts and permissions on computers belonging to the domain 
centrally instead of on each individual computer. This allows users to use a 
single user account to gain access to network resources on multiple computers on 
the domain and gives the administrator the ability to tightly control what type 
of access rights users have to what resource. If you run into problems accessing 
a network resource on a network that is managed with domains, you should contact 
the network administrator for assistance. 
 
Gateway configuration 
 
A gateway is the next configurable device in the chain of hops along a network 
path from the PC that will redirect the transmitted data to the next hop 
depending on its configuration. This is usually a router.  
 
Scenario 1 - PC -> DSL/Cable modem: The gateway is on the ISP's network and 
cannot be accessed or configured by the user. If everything checks out on the PC 
and the problem seems to be at the next hop, the ISP's gateway, contact the ISP 
for assistance. 
 
Scenario 2 - PC -> Gateway device: Log into the gateway device and verify that 
its public interface / the WAN link is configured properly with the values 
provided by the ISP, i.e. the IP address and subnet mask, gateway IP address, 
DNS server IP address (if statically configured) or set up for DHCP and has 
received this information from the ISP's DHCP server. It is very common for 
cheap DSL lines that they are "on demand" connections, meaning they are only  
active when you need them, which is more economical for the ISP for several 
reasons such as bandwidth and IP address allocation. In this case the ISP 
usually requires you to contact them and announce that you want to initiate a 
connection before they will give you the necessary information. This is usually 
done via PPPoE (Point-to-Point-over-Ethernet). If your ISP uses this method, you 
will need to select the PPPoE option in your gateway device and enter the  
necessary user login information provided by the ISP. 
 
Scenario 3 - PC -> Hub/switch -> Gateway device -> DSL or cable modem: See  
scenario 2. 
 
Scenario 4 - PC -> Office network: Check with the network administrator to have 
the gateway / router checked. 
 
Gateway firewall 
 
Scenario 1 - PC -> DSL/Cable modem: n/a 
 
Scenario 2 - PC -> Gateway device: Gateway devices for home and small office 
networks usually include a firewall of some sorts. Check the firewall rules and 
verify that there are no custom rules that may be blocking network connectivity. 
Use the reset to default option if available. 
 
Scenario 3 - PC -> hub/switch -> gateway device -> DSL or cable modem: See  
scenario 2. 
 
Scenario 4 - PC -> Office network: n/a 
 
If everything checks out within the network and up to the gateway but fails 
after that, the problem most likely lies with the ISP. Contact the ISP to report 
the problem and get assistance. Before you call, make sure you have all the 
information handy that you gathered during your troubleshooting, and explain the 
troubleshooting steps you have already done. This will make their job easier and 
help resolve the issue. If this is an office network, contact the network 
administrator instead. 
 
Log Files 
 
When troubleshooting computer problems, the chances are good that there may be 
important clues recorded in log files. For example, Windows keeps several log 
files where it records system, application, and security information including 
error messages. You can access these logs by right-clicking My Computer, 
selecting Manage, then navigating to Computer Management / System Tools / Event 
Viewer and clicking each log.  
 
Another log to consult is the firewall log. If you have a software firewall 
running on your PC, open it and look for a log. If you are using a gateway with 
a firewall, access its admin console and look for a log. Either one will most 
likely have entries for blocked network traffic that will give you a clue what 
was blocked why. 
 
Hardware failure 
 
Last but not least, if you have triple-checked that everything is configured 
properly but it still doesn't work, also consider the possibility of a hardware 
failure. Maybe a port on your hub/switch/gateway device is bad, so try another 
one. Does the device even have power? Maybe its power adapter failed. Is it hot 
to the touch? Maybe it overheated. Unplug it for 10 minutes and let it cool 
down, then try again. Maybe a power surge scrambled its memory. Unplug it for 
five seconds, then plug it back in again and try again. Try resetting the device 
to factory defaults. Maybe the suspect device that you identified by process of 
elimination is fried altogether. Replace it with a different one and see if that 
corrects the issue. 
 
Conclusion 
 
Boy, that was a lot of information, wasn't it? Hopefully you have learned a lot 
about the basics of networking and got a better understanding of what makes a 
network tick. In addition, you should now realize that troubleshooting a network 
connection is a pretty logical process and that there are many things you can 
easily check yourself to resolve the problem yourself within a reasonable amount 
of time. 
 
 
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