Basic info on ports/services

[Randy Edwards <redwards@golgotha.net>]

Can someone point me to some URLs/info about port descriptions, what runs on
them, and whether they're asbolutely needed or not?

For example, what's the discard service (9), daytime (13), or time (37), or
what specific ports does Debian's nfs-kernel-server use/require?

I understand the basics of inetd.conf and services, but without a more
verbose description it makes it difficult to use them fully.

Also, is there an online site where I can run a port scan at my own machine
(i.e. externally, since my firewalling rules are different for internal
machines)?  I know <http://www.grc.com> does that, but I have a suspicion
it's not checking all ports.

-- 
 Regards, | Moore's Law: Every 2 years CPU power will double.
 .        | 
 Randy    | Gates' Law: Every 18 months software speed will halve.