http://books.gigatux.nl/mirror/networksecuritytools/0596007949/networkst-CHP-7-SECT-4.html

netstat -c –Continuous output
netstat -r –Displays routing table
netstat -ie –Network Interfaces
Displaying all Connections
netstat -a
Displaying all TCP
netstat -at
Displaying all UDP
netstat -au
Displaying all listening TCP Ports
netstat -lt
Displaying all listening UDP Ports
netstat -lu
Process Identification
netstat -p
netstat -atp –Shows service name
Displaying only listening TCP connections
netstat -tnl
Displaying only listening UDP connections
netstat -unl
Combination: netstat -nlpt –Shows process name and PID
Displaying a particular port
netstat -anp | grep:443