arp ip addr to phys addr
7 echo Whatever you type in, the host repeats back to you, used for ping
9 discard Dev/null -- how fast can you figure out this one?
11 systat Lots of info on users
13 daytime Time and date at computer's location
15 netstat Tremendous info on networks but rarely used any more
19 chargen Pours out a stream of ASCII characters. Use ^C to stop.
20 FTP data (File Transfer Protocol)
21 FTP commands (File Transfer Protocol)
22 ssh secure shell login -- encrypted tunnel
23 telnet Where you log in if you don't use ssh:)
25 smtp (send mail transfer protocol) Forge email from Bill.Gates@Microsoft.com
37 time
39 rlp Resource location
43 whois Info on hosts and networks
53 DNS (domain Name service)
68 DHCP (dynamic host control protocol)
70 gopher Out-of-date info hunter
79 finger Lots of info on users
80 http (hyper text transfer protocol)
110 pop3 (post office protocol, v3) Incoming email
119 nntp (network news transfer protocol) Usenet news - forge posts, cancels
161 snmp (simple network management protocol)
194 irc (inter relay chat)
389 ldap (lightweight directory access protocol)
443 ssl (secure socket layer)
512 biff Mail notification ? 513 rlogin Remote login who Remote who and uptime 514 shell Remote command, no password used! syslog Remote system logging -- how we bust hackers 520 route Routing information protocol
1433 Microsoft SQL Server 1521 Oracle SQL 3306 mySQL 5800 VNC 5900 VNC 6000 X Windowing System