host is a simple tool for looking up DNS records. Usage: host [-aCdlriTwv] [-c class] [-N ndots] [-t type] [-W time] [-R number] [-m flag] hostname [server] host -t ns domain.com - get nameservers host -t mx domain.com - get mx records host www.domain.com - get IP address Continue Reading
host
tcpdump
awk
netcat, ncat & sbd
netcat Netcat is a tool that reads or writes to/from TCP and UDP network sockets. It can act as a client or server or scanner. The simplest possible use is: As a network client nc 10.0.0.1 25 - netcat will attempt to connect (as a client by default) to port 25 (using TCP by default) on that IP address. It accepts a number of options: -v = verbose - give more information -vv = very verbose -n = no DNS lookup As a listener nc -nlvp 5555 - will bind to local port 5555 and listen for incoming connections -l = listen mode -p = port number You can then use another instance Continue Reading