Linux - Network Auditing NMAP (1)

Nmap ("Network Mapper") is a free and open source (license) utility for network exploration or security auditing.
Many systems and network administrators also find it useful for tasks such as network inventory, managing service upgrade schedules, and monitoring host or service uptime.
Nmap uses raw IP packets in novel ways to determine what hosts are available on the network, what services (application name and version) those hosts are offering, what operating systems (and OS versions) they are running, what type of packet filters/firewalls are in use, and dozens of other characteristics. It was designed to rapidly scan large networks, but works fine against single hosts. Nmap runs on all major computer operating systems, and both console and graphical versions are available


[root@lsvr02 ~]# nmap 127.0.0.1

Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2007-10-25 09:47 HKT
Interesting ports on lsvr02 (127.0.0.1):
Not shown: 1668 closed ports
PORT STATE SERVICE
21/tcp open ftp
22/tcp open ssh
80/tcp open http
111/tcp open rpcbind
139/tcp open netbios-ssn
199/tcp open smux
200/tcp open src
443/tcp open https
445/tcp open microsoft-ds
1023/tcp open netvenuechat
3306/tcp open mysql

Nmap finished: 1 IP address (1 host up) scanned in 0.201 seconds