i've used it few times on a bsd server, the command was :
nmap -v -a -p0 10.10.1.1 (replaced by your actual ip) and it gives pretty good output like :
quote:
host my.host.tld (ip goes here) appears to be up ... good.
interesting ports on my.host.tld (ip goes here):
not shown: 1670 closed ports
port state service version
21/tcp open ftp proftpd 1.2.10
22/tcp open ssh openssh 4.2p1 (freebsd 20050903; protocol 1.99)
25/tcp open smtp qmail smtpd
53/tcp open domain
80/tcp open http apache httpd 2.0.54
106/tcp open pop3pw poppassd
443/tcp open ssl/http apache httpd 2.0.54
465/tcp open ssl/ssl openssl
3306/tcp open mysql mysql (unauthorized)
8443/tcp open http apache httpd 1.3.33 ((freebsd) mod_ssl/2.8.22 openssl/0.9.7e php/5.0.5)
no exact os matches for host (if you know what os is running on it, see
http://www.insecure.org/cgi-bin/nmap-submit.cgi).
tcp/ip fingerprint: