NETSTAT

This command displays protocol statistics and gets information about TCP/IP connections.

• Command Syntax
  • Netstat [-a] [-e] [-n] [-s] [-p protocol] [-r] [interval]
• Command Switches
  • -a: displays connections and listening ports and their current state, but not the server sessions.
  • -e: displays Ethernet stats.
  • -n: displays active connections, listed by IP address.
  • -s: displays per-protocol statistics for IP, ICMP, TCP, and UDP.
  • -p protocol: displays active connection statistics for the chosen protocol (TCP or UDP), can use with the -s switch for more information.
  • -r: displays the contents of the routing table.

ipconfig/winipcfg

These utilities display IP-addressing information for the local network adapter(s) or a specified NIC. IPCONFIG is a command-line tool; WINIPCFG is GUI-based.

• Command Syntax
  • ipconfig [/all | /renew [adapter] | /release [adapter]]
• Command Switches
  • /all: all information about adapter(s).
  • /renew: renew DHCP lease information for all local adapters if none is named.
  • /release: release DHCP lease information thereby disabling TCP/IP on this adapter.

FTP

This utility is used to transfer files between server and client. This is a reliable method of data transfer because it uses TCP. There is a long list of session commands for file management.

• Command Syntax
  • ftp [-v] [-n] [-i] [-d] [-g] [-s: filename] [hostname]
• Command Switches
  • -v: suppresses any display server responses (@echo off in DOS).
  • -n: prevents automatic login when connection has been established.
  • -I: turns off interactive prompting during file transfer.
  • -d: displays all ftp commands exchanged between client and server; for debugging.
  • -g: disables the globbing capability.
  • -s: filename - specifies a text file containing ftp commands and then runs the commands within the file, similar to a batch file.
  • hostname: the host to connect to and MUST be the LAST parameter specified.

Ping

Will send ICMP echo packets to verify connections to a remote host (or test the local TCP/IP installation if using the loopback address).

• Command Syntax
  • ping [-t] [-a] [-n count] [-l length] [-f] [-i ttl] [-v tos] [-r count] [-s count] [[-j host-list] | [-k host-list]] [-w timeout] destination-list
• Command Switches
  • -t: ping until interrupted.
  • -a: ping address and resolves host name.
  • -n count: send number of echo packets.
  • -l length: send echo packets of a specified size.
  • -f: sends a DO NOT FRAGMENT command to gateways.
  • -i ttl: sets the TTL field (Time To Live—the number of hops between nodes allowed, before ending).
  • -r count: records the route of the outgoing and returning packets.
  • destination-list: specifies the remote hosts to ping, by domain name or by IP address.

Nslookup

Queries a name server and finds out which name resolves to which IP address.

• Command Syntax
  • Type=mx: returns the email server for that domain.
  • Domain=<domain name>: sets the current domain name to the domain name in <domain name>.
  • Retry=X: specifies the number of retries with “X” representing the number of specified seconds.