Displaying the Routing Table：
netstat -nr
Displaying Interface Statistics:
netstat -i
Show the address resolution (ARP) tables:
netstat -p
Displaying Connections:
netstat -ta (linux)
netstat -a -f af:inet (opensolaris)

http://www.faqs.org/docs/linux_network/x-087-2-iface.netstat.html
http://docs.sun.com/app/docs/doc/816-5166/netstat-1m?l=en&a=view&q=netstat