Tag Archives: Network Tools

How to troubleshoot a slow computer network?

Troubleshoot Network - Ping
Pinging Google

Your network is slow. What do you do to make it faster?
The answer is not simple and the reason for your slow network could be a lot of things. You have to take a step by step approach and isolate the bottleneck. Once you isolate the point of failure it is easier to find the problem.

Many times a packet sniffer will help you find the problem faster. A good free packet sniffer is Wireshark. Another packet sniffer is Microsoft Network Monitor.

Here is a list of Windows-based network tools that can help you troubleshoot almost any problem in a Computer Network:
Ping – a network utility to test if a computer is up and reachable or not. Ping uses the ICMP protocol to send echo requests.
Nmap – a port scanner. You need a port scanner to enumerate open ports and live IP addresses.
Tracert – a utility that traces the path of a network packet enumerating all of the routers that it passes through.
Wireshark – a packet sniffer.
Netstat – a utility that enumerates all the open ports on the local computer.
Ipconfig – a utility to list or modify the properties of a network adapter.
Netsh – a powerful Windows utility to modify various network properties. It is a scripting utility that basically controls every aspect of the Network on a Windows computer.
One of the cool usages of the netsh is to reset the TCP/IP stack to the defaults without the need to uninstall and reinstall the TCP/IP protocol as we needed with the older OSs.
Route – enables the view and manipulation of routing.
Nslookup – a name resolution utility. Very useful to check DNS servers and validity of name records.
Arp – a utility that allows you to get information about MAC address to IP address resolution.
Getmac – Provides the MAC address and lists associated network protocols for all network cards for a local or remote computer.
Getname – displays the computer name.
PathPing – Combines the functions of Traceroute and Ping, very powerful tool.
Net services commands – Performs a broad range of network tasks such as Network mapping, authentication, controls services, etc…

If you are not sure how to use these tools read the Help or from the command line, (all of these are command line tools), issue the command with the help option, for instance: “pathping /?”. This will give you a list of other valid options.  

This article is part of a five posts series regarding Network Troubleshooting.

  1. How to troubleshoot a slow computer network?
  2. Troubleshoot a Slow Network – The entire Network is Slow
  3. Troubleshoot a Slow Network – Slow Server
  4. Troubleshoot a Slow Computer Network – Only One Computer on the Network is Slow
  5. Troubleshoot a Slow Computer Network – Your Computer is Slow and Not the Network

How to Make an Ethernet Patch-cord

Tools and supplies needed for a network patch cord:

  • Twisted pairs cable
  • Scissors or cutter pliers
  • RJ45 male connectors
  • Good quality Crimper

Ethernet Network Tools
Ethernet Network Tools

Utp Cable Stripp
Utp Cable Stripp
Start by stripping the pvc cover off the twisted pairs cable. Remove about 3inches (7cm).
Separate and untwist the wires. Arrange the wires in order using your favorite cabling standard. Use the same standard for both of your ends.

If you are redoing just one end make sure you are copying the other one, otherwise your patch cord will not work.
I always use the same standard so I don’t get confused when I am redoing cables. I use the T568B standard because there is a little trick to remember the wires order. See at th post Mnemonic for Network Cable pinout for a trick on how to remember the cable order.

Network Cable Standards
Network Cable Standards – Wires order

Straighten UTP Wires

Straighten UTP Wires
Straighten Wires
Straighten the wires, making sure you keep them in order. It is very easy to mix the wires after putting them in order.
If doing this feels painfully difficult, try to find RJ45 male connectors with guides for wires. The guides keep the wires in place and help you insert them into the connector. It is a real help for a beginner.
Cut the wires just a little longer than the RJ45 connector.

Cut UTP wires
Cut UTP wires

Insert Wires RJ45
Insert Wires RJ45
Insert the wires into the connector ensuring that you keep them in the correct order. To keep the wires straight push up a little against the upper side of the connector while you slide them. This procedure helps you keep the wires aligned while inserting them.
When you reach the end of the connector the exterior jacket will be outside of the connector. Make sure you push a little more so that the jacket gets inside. at the time of the crimping the plastic indentation on the connector gets pressed on the exterior jacket, conferring the patch-cord more rigidity and resistance. If the jacket doesn’t get into the RJ45, the wires will be loose inside the connector. This will cause the wires to move and loosen up the point of insertion.

Insert Wires RJ45
Insert Wires RJ45

Crimp UTP RJrj45
Crimp UTP RJrj45
Crimp the connector maintaining the wires and the cable jacket inside the connector.
Inspect the cable, verifying that the wires are in the correct order.

Inspect RJ45
Inspect RJ45

Compare Ends RJ45
Compare the Ends patch cable
Proceed to the other end and untwist the wires. Maintain the same wires order. Redo the same operations as above.
Compare the two ends. Make sure they are identical. If they are not your cable will most likely not work.
For a 100Mb network only two pairs are needed, the active wires are at the pins 1,2,3 and6. For a 1Gb network, all of the four pairs are needed.

Compare RJ45 Ends
Compare RJ45 Ends

Network Cable Tester
Network Cable Tester
Depending on the nature of your job you might need to use a cable tester. For a small network a simple continuity tester will be sufficient. The tester injects a signal on one end and it tests the signal at the other end.
If the cable is correctly crimped all of the LED’s will light up in order. The shield LED might not light up if your connectors are not a shielded.
For bigger networks you will need a more complex tester that can measure attenuation, cable length, and can even give you an overall result of the point to point capability. This type of testers can sum up the various aspects of a measurement and tell you if your segment qualifies for a CAT3 or CAT5 or CAT6 connection.

How to Build a Computer Network

If you own or manage two or more computers you need to connect your computers in a wired network to share Internet Connection and other services.
Here is a complete How To Build a Network.

Whether you are doing it at home or at your workplace, creating a computer network is not very difficult if you are a handy person and you have basic knowledge of computer networks. We will cover here most of the concepts you need to make your own LAN.
Computer Network
The series of articles will show you how to create a physical network and how to configure it to provide various services to your network users. We will focus on TCP/IP networks as this is the most common networking protocol.

Why Do You Need a Network?

You need a network if you need to share services for two or more computers.
Services that can be shared include: File sharing, sharing a network printer, Internet sharing, email services, Intranet, media broadcasting, etc…
In a home network, it is very common to share a printer and the Internet Connection.
In Business environment, the network becomes more complex and many more services will be needed to accommodate the use of many computers in a single network. Such services are DHCP – for automatic IP configuration, DNS – for name to IP resolution, corporate email, Proxy Server – for increased security on Internet, Intranet server – this is a private web server, VOIP phone system, etc…

What are the Limitations of My Network

You Ethernet cables are limited to 100m between any two active devices. If you need more than 100m between any two active devices such as computer and switch or computer to computer, you need to add a repeater or a hub, a switch will work as well, at each additional 100 meters, (or 333 ft.).
Depending on your materials and equipment, your network can run at 10Mb/s, 100Mb/s or 1Gigabit/s.
The most usual is to use Cat 5 or Cat 5e cables and connectors. A Cat 5 network can provide a speed up to 1000Mb/s.
If you need to connect at longer distances the more suitable solution are
Coaxial cable – up to 500M, speed 10Mb. You need special repeaters or hubs or special network cards.
The fiber optic – 10Km or more, speed up to 100Gb, depending on the equipment. It is the most expensive solution; the price though can be affordable for slower connections. For slower connections, most of the cost will consist on running the cable between the two points.
DSL is the cheap way to connect two remote offices if you have an available copper pair between the two offices.

What Do I Need to Make My own Network?

To make your own Ethernet Network you need the following equipment:
UTP/STP networking cable, RJ-45 connectors, Crimping tool, Punch down tool, Keystone Jacks, Wire stripper / Knife, Network Tester, Patch Panel, Network Switching device. The list includes also a stud finder, drywall saw, measuring tape, mounting plate, fish tape, ladder, and the usual tools such as screwdriver, drilling machine, hammer, etc…
Ample descriptions on the tools and materials are provided by following the links.

Computer Network Planning

The typical Ethernet Network has a star topology. That means that you have a central device, (network switch), that connects all of your network participants. This is important for your planning since you will have to run all of your cables to a central point. Make your measurements and place your central point in such manner that all of your cables are 100m or less. This includes the patch-cord as well.
If you have computers farther than 100m you will need to install a repeater. Alternatively you can use other types of connection, (coax, fiber optic, etc…), see the limitation paragraph.
When you run a cable consider the maximum amount of devices that can be stuffed into that office. It is a lot cheaper to run an extra cable or two per each office location than to run a single cable after the initial installation.
Install the keystones as close as possible to the actual location of the computer. Plan this thoroughly and pick the best location so that the patch-cord is out of the way.
Buy extra cable and extra connectors.
Use common paths for your cables whenever possible. If you run ten cables at once saves a lot of work and time.
Plan your cable route. Use ceiling whenever possible, it is the easiest path. Avoid running the cables near big electromagnetic sources.

Buying Computer Network Tools and Supplies

Do not buy cheap tools and materials. If you do, you will be penalized in different ways:
At the installation time you will get all sorts of problems trying to connect poor materials, cheap cable will be damaged more easily when manipulated, connectors will break easier.
In time the quality of the network will decrease if poor supplies and tools are used.
Overall experience and quality will be very poor if you get too cheap. If buying expensive tools is not justified, (a one time job), try to borrow good tools and don’t buy cheap ones.
Follow the links to learn what to look for when you are buying specific materials.
Now that you planned and bought all the Networking tools and supplies you can proceed to the Running the Cables for a Computer Network.