The useful commands a Server administrator should know

Netstat command

               Netstat is a command line diagnostic tool which displays the information about TCP/IP  network protocol. The  basic function of netstat is to check which ports are active on the machine. It also gives information about the different ports such as the port number, the associated protocol and status. The information is helpful in getting information about which ports are closed or open and to determine which ports are vulnerable to attacks.

           When you enter netstat on the command prompt , it provides you with a list of information about the connection. It also provides details such as the different protocols being used , name of your machine, TCP/IP connection, foreign address ,local address and status of connection.

Ipconfig command

              The basic function of Ipconfig is to display IP address , subnet mask and default gateway of each network adapter. It can also be used to display or reset the DNS cache, refresh registered DNS names, set and display the DHCP  class IDs for an adapter.

       Ipconfig is very useful for diagnosing DHCP problems. When you are using a DHCP server, this command displays the address assigned to the adapter. If you find that the address id 0.0.0.0 then it indicates that the connection between your system and DHCP server is lost or else it means that the server is not functioning properly.

Winipcfg command

             Winipcfg is a command which provides IP addressing information. Winipcfg command is used if you are running a version of Windows earlier than Windows 2000 such as 98 or 95 . Winipcfg command provides network related information such as the IP address, subnet mask, default gateway,DHCP server and WINS server. It also allows you to release or renew the adderss, if the IP address is being  assigned via DHCP or BOOTP.

ARP command

              Address Resolution Protocol (ARP) performs the function of linking IP address of a node on network to its hardware address – MAC . This  process in known as IP address resolution . ARP generates an ARP  table which contains the mapping of IP address to MAC address, Various ARP command options can be used to display or change the values in ARP table.

Nbtstat command

                 Nbtstat is a MS-Dos tool used to troubleshoot NetBIOS name resolution problems. It can be used when WINS server is not accessible or it is not resolving a name correctly. NBTSTAT displays protocol information and current TCP/IP connection using NetBIOS over TCP/IP. This command also helps to add or remove  the NetBIOS entries.