. Compiler: gcc
. Crack: John the Ripper (AKA john)
. Debugger: gdb, xxgdb, strace, ptrace
. Encrypt: ssh, scp, pgp
. Firewall: iptable, ipchains, tcp_wrapper, ip filter
. Library: libnet, libpcap
. Log: syslog, chkrootkit, zap
. Management: Net-snmp
. Proxy: socks5, rinetd
. RootKit: Linux RootKit
. Scanner: nmap (only one is enough!), ADMsmb (SMB scanner), cgichk
. Script: perl, php, sed, awk
. Server: Samba, Apache, Sendmail, Bind, NFS, NIS
. Sniffer: tcpdump, ethereal, ettercap, sniffit, ADMsniff, linsniffer.c
snort, dsniff
. Spoof: hping
. Web/FTP client: lynx, wget, ftp
. Misc: telnet (don't forget it!), sudo

#!/bin/sh

PORT="21,22,23,25,79,80,110,513,514"

for host in `nmap -n -sP xxx.xxx.xxx.1-255 | sed -n 's/) appears to be up.//p' | sed -n 's/.*(//p' | sort` ; do
echo -n "scanning host: $host ..."

nmap -p ${PORT} -O -sS ${host} >> log
echo >> log

echo "done."
done

Starting nmap V. 2.54BETA30 ( [عزيزي الزائر يتوجب عليك التسجيل للمشاهدة الرابطللتسجيل اضغط هنا] )
Interesting ports on (xxx.xxx.xxx.xxx):
(The 8 ports scanned but not shown below are in state: closed)
Port State Service
21/tcp open ftp
22/tcp open ssh
23/tcp open telnet
111/tcp open sunrpc

Remote operating system guess: Sun Solaris 8 early acces beta through actual release
Uptime 5.226 days (since Tue Jan 29 15:50:30 2002)

Nmap run completed -- 1 IP address (1 host up) scanned in 7 seconds