Identify and repair faults in networks

Measuring equipment

LAN tester
With the help of a LAN tester, check whether all cable threads (pins) from the patch panel in the network socket are correctly connected. For each test pin, the tester provides a glow (LED), which illuminates when receiving and sending the signal is performed correctly and does not light up otherwise.

Digital Multimeter
In addition to copper permeability control, a digital multimeter can perform voltage and resistance measurements. To ascertain the correct connection of the cable head to the coaxial cable BNC, the resistance between the metal sheet protector and the internal cable conductor is measured The digital multimeter is often used for twisted-pair cables. With its help, defects are found as short links between cable yarns and protective sleeves, or defects in network pluggable ports and patch panels.

Cable control equipment
In case of missing the labeling of the gates to the network sockets or to the patch panel, with the help of the device for controlling the lines it is possible to quickly identify the port that belongs to the desired cable. Quick identification is done by means of a voice signal that emits device. It connects directly to the patch panel port, or to the network socket.

Cable measuring equipment
The device for measuring the electrical characteristics of the connection (cable) can measure the capacity, resistance, voltage, signal loss losses, etc. Using a graphic that appears on the display screen of the device, you can instantly distinguish the faulty yarns, or the interruptions in the cable assembly, in order to make it easier to eliminate them. First of all with this device you can To identify cable defects that are not distinguished by the naked eye.
Basic Diagnostic Network Commands.
These commands are used to diagnose network connection issues. Commands are executed by the command prompt. To open the command prompt click on Start - Run, type cmd, and then press ENTER.

Net session
Net session displays the open / active links of other devices with your system. To execute the net session command, type net session.
nslookup
Nslookup is a diagnostic command, which displays information from Domain Name System (DNS) name servers. This command can be used to diagnose problems with DNS configuration. To start typing nslookup.
arp
ARP makes TCP / IP resolution at MAC (Media Access Control) address. All network protocols should use the physical hardware MAC address to connect to a remote system. ARP commands work only if you have an address translation table. To display the Ethernet address of a TCP / IP system with IP address 192.168.100.100 enter arp 192.168.100.100.
nbtstat
Nbtstat displays statistics and system connections that are using NetBIOS over TCP / IP. You can use a parameter (eg -s) to list the NetBIOS name table for a remote host. You can also reload any LMHOSTS file using the -r parameter. To display all NetBIOS sessions over TCP / IP in the system, type nbtstat -s.
tracert
Tracert is a utility that you can use to verify if there is a router path between your system and a remote system. Tracert reports the number of hops needed to find a certain destination and router on each pass. To trace the router to a myhost system, enter myhost tracert.
ipconfig
Ipconfig displays the data in the TCP / IP system configuration. Ipconfig also displays the address of the DNS server and the Windows Internet Naming Service (WINS). To display all TCP / IP configurations, enter ipconfig / all.
Route print
Route print displays the routing table of an NT system. The route print command shows the default routes used by the NT system, and the remote systems in the Routing Information Protocol (RIP). To execute Route Print, enter the print route.
telnet
Telnet allows you to connect to a specific gateway on a remote system and find out if a socket application is listening to that gateway. To execute telnet, type telnet.
netstat
Displays connection status and statistics of TCP / IP or UDP. The netstat command, after execution, shows the name of the local computer, the remote computer name, the connection port, and the current connection status. Parameters can be used with the command, such as -r that provides information about the routing, or -s that presents statistics about the protocols. To execute netstat, type netstat.
ping
The ping command works with all TCP / IP systems and identifies the main problems of network connections. Ping uses the Internet Control Message Protocol (ICMP) to send a data packet to a remote host, and then expects that the host in question will return the data packet back.
Net view
Presents a list of file and print shares of the computer that is working.
At the command prompt, type net view \\\name_computer, and then press ENTER