fluffy:/usr/bin# nmap -sV -O -P0 localhost

Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2008-02-01 00:15 CET
Interesting ports on localhost (127.0.0.1):
Not shown: 1677 closed ports
PORT    STATE SERVICE VERSION
111/tcp open  rpcbind  2 (rpc #100000)
113/tcp open  ident   OpenBSD identd
631/tcp open  ipp     CUPS 1.2
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:
SInfo(V=4.11%P=i686-pc-linux-gnu%D=2/1%Tm=47A256B3%O=111%C=1)
TSeq(Class=RI%gcd=1%SI=42F474%IPID=Z)
TSeq(Class=RI%gcd=1%SI=42F55D%IPID=Z)
T1(Resp=Y%DF=Y%W=8000%ACK=S++%Flags=AS%Ops=MNNTNW)
T2(Resp=N)
T3(Resp=Y%DF=Y%W=8000%ACK=S++%Flags=AS%Ops=MNNTNW)
T4(Resp=Y%DF=Y%W=0%ACK=O%Flags=R%Ops=)
T5(Resp=Y%DF=Y%W=0%ACK=S++%Flags=AR%Ops=)
T6(Resp=Y%DF=Y%W=0%ACK=O%Flags=R%Ops=)
T7(Resp=Y%DF=Y%W=0%ACK=S++%Flags=AR%Ops=)
PU(Resp=Y%DF=N%TOS=C0%IPLEN=164%RIPTL=148%RID=E%RIPCK=E%UCK=E%ULEN=134%DAT=E)


Service Info: OS: OpenBSD

Nmap finished: 1 IP address (1 host up) scanned in 16.068 seconds