Monday, December 29, 2014

Networking testing tools.


No matter how much wireless networking there is, you have to have at least a small amount of hardwire. There are some tools that might be nice to have if you are using more than the minimal amount of cabling (aka hardwire).

The tone generator helps you trace where a wire is routed through. Personally, in all my years as a tech, I think we used only just once.



When trying to see if a network wall outlet was live, I used an end tester. you would use the tester coupled to a patch cable (short length of network cable).




If things are working correctly, all four lights should be lit. Though with this unit, have seen a few false positives.If all the light are not lit, it can be a bad female plug or some fault down the line. Generally has only one port.


To test a single cable. Connect both ends to the tester.  You would not connect it to a network or it will get damaged. You will need access to both ends of a cable to test.


Generally these tools are used when preparing a cable. The unit will generally check one wire in the cable at a time. If the lights do not show in sequence then one or both ends of the cable have to be redone. If lights do not show up is also a symptom of a bad cable.

If all is well then you need to check to see if there is data coming down the line. There are some expensive tools, but usually a laptop with basic networking software tools will do just fine.  Generally, when you hook to a network, the network will send data in the form of TCPIP. It will want to give a network address to use (sort of a phone number).  So we can find out by hooking the laptop whether that data has been sent.
If you are not getting an ipaddress you might see something like this:

 $ ifconfig
eth0      Link encap:Ethernet  HWaddr 00:00:00:00:00:00 
          UP BROADCAST MULTICAST  MTU:1200  Metric:1
          RX packets:77134 errors:0 dropped:0 overruns:0 frame:0
          TX packets:59943 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:66488832 (66.4 MB)  TX bytes:9327481 (9.3 MB)

Then if the network is sending you an ipaddress, it might look something like this:

$ ifconfig
eth0      Link encap:Ethernet  HWaddr 00:00:00:00:00:00 
          inet addr:192.168.1.188 Bcast:192.168.1.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1200  Metric:1
          RX packets:77146 errors:0 dropped:0 overruns:0 frame:0
          TX packets:59990 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:66490251 (66.4 MB)  TX bytes:9340858 (9.3 MB)

In this case the network address is 192.168.1.188 and everyone should be able to reach you at that network address.  But is the network available? You can use the ping command to see if a site is available. You get  to see Google network phone number.

$ ping -c1 www.google.com
PING www.google.com (173.194.37.50) 56(84) bytes of data.
64 bytes from atl14s07-in-f18.1e100.net (173.194.37.50): icmp_seq=1 ttl=53 time=30.0 ms

--- www.google.com ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 30.036/30.036/30.036/0.000 ms
You can go one step further and see what places are on the way to google

$ traceroute  www.google.com

or you can go to the web..






Lastly, you use special programs to see what kind of information is on the network. These are known as packet sniffers. One such program is Wireshark. These tools can also be used for wireless.
 


Ethernet packing sniffer interfaces:





Also see: http://www.instructables.com/id/Lets-get-wired/

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