I'm a newbie to networking but I do know that nmap is no toy. My
question is if I ...

nmap -sT localhost

....like
'http://en.wikibooks.org/wiki/Reverse_Engineering/Port_Scanners' says
would I be only seeing open ports on my own machine and could this be
done while my computer is a stand alone work station. I did look up the
meaning of localhost and it seemed like it was your own workstation but
I wanted to be sure.

Thanx.

On 1 Nov 2006, in the Usenet newsgroup comp.protocols.tcp-ip, in article
<1162423297.982219.127860@h54g2000cwb.googlegroups .com>, freerpress0@yahoo.com
wrote:

>I'm a newbie to networking but I do know that nmap is no toy.

Good. Note that an nmap scan _may_ trigger a firewall if the target
system has one installed. That may give false results, as well as get you
in trouble with who-ever owns that computer.

>My question is if I ...
>
>nmap -sT localhost

nmap comes with a _vast_ amount of documentation and papers.

>would I be only seeing open ports on my own machine and could this be
>done while my computer is a stand alone work station.

OK - your headers say Linux, so start with '/sbin/ifconfig -a' which will
show all interfaces on your system. You should _always_ have a loopback
(interface "lo" at 127.0.0.1), and you may have one or more others,
depending. For the simple 'nmap -sT localhost' scan, you'd actually see
a lot more by using the command '/bin/netstat -aptun'. See the man pages.

>I did look up the meaning of localhost and it seemed like it was your own
>workstation but I wanted to be sure.

http://tldp.org/guides.html

* The Linux Network Administrator's Guide, Second Edition
version: 1.1
authors: Olaf Kirch and Terry Dawson
last update: March 2000
ISBN: 1-56592-400-2
available formats:
1. HTML (read online)
2. HTML (tarred and gzipped package, 690k)
3. PDF (1.5MB)

You also should have a bunch of HOWTOs on your system, probably in
/usr/share/HOWTO or similar - look at

45604 Apr 18 12:20 Networking-Overview-HOWTO
71626 Apr 4 2004 Unix-and-Internet-Fundamentals-HOWTO

"localhost" (or to give it it's full name "localhost.localdomain") is always
"this" computer. It's how the different parts of software talk to each other.

[compton ~]$ /sbin/ifconfig | grep -A1 Link
lo Link encap:Local Loopback
inet addr:127.0.0.1 Bcast:127.255.255.255 Mask:255.0.0.0
--
eth0 Link encap:Ethernet HWaddr 00:C0E:57:40:F4
inet addr:192.0.2.22 Bcast:192.0.2.255 Mask:255.255.255.0
[compton ~]$

Here, this system has an Ethernet card installed, and configured as
192.0.2.22. That is how others can "talk" to this computer, but if I want
to send a packet to this address, it would go on the loopback. The Linux
(and most other O/S) kernel "knows" it's own IP addresses, and does this to
avoid unnecessary bandwidth on the Ethernet

Old guy