Cuando escaneo con el nmap mi propia ip, incluso con las opciones mas basicas, todo va bien, me da todos los detalles que quiero ver. Pero a la hora de analizar un host remoto, no me dice nada, ni los puertos que hay abiertosd ni el OS. Esto es lo que me pone:

root@slax:~# nmap -vv -A -sS -P0 -sV -O 79.151.49.6

Starting Nmap 5.21 ( http://nmap.org ) at 2011-01-07 19:26 GMT
NSE: Loaded 36 scripts for scanning.
Initiating Parallel DNS resolution of 1 host. at 19:26
Completed Parallel DNS resolution of 1 host. at 19:26, 0.07s elapsed
Initiating SYN Stealth Scan at 19:26
Scanning 6.Red-79-151-49.dynamicIP.rima-tde.net (79.151.49.6) [1000 ports]
SYN Stealth Scan Timing: About 15.50% done; ETC: 19:29 (0:02:49 remaining)
SYN Stealth Scan Timing: About 30.50% done; ETC: 19:29 (0:02:19 remaining)
SYN Stealth Scan Timing: About 45.50% done; ETC: 19:29 (0:01:49 remaining)
SYN Stealth Scan Timing: About 60.50% done; ETC: 19:29 (0:01:19 remaining)
SYN Stealth Scan Timing: About 75.50% done; ETC: 19:29 (0:00:49 remaining)
Completed SYN Stealth Scan at 19:29, 201.81s elapsed (1000 total ports)
Initiating Service scan at 19:29
Initiating OS detection (try #1) against 6.Red-79-151-49.dynamicIP.rima-tde.net
(79.151.49.6)
Retrying OS detection (try #2) against 6.Red-79-151-49.dynamicIP.rima-tde.net (7
9.151.49.6)
Initiating Traceroute at 19:29
Completed Traceroute at 19:29, 0.15s elapsed
Initiating Parallel DNS resolution of 5 hosts. at 19:29
Completed Parallel DNS resolution of 5 hosts. at 19:29, 2.57s elapsed
NSE: Script scanning 79.151.49.6.
NSE: Script Scanning completed.
Nmap scan report for 6.Red-79-151-49.dynamicIP.rima-tde.net (79.151.49.6)
Host is up (0.14s latency).
All 1000 scanned ports on 6.Red-79-151-49.dynamicIP.rima-tde.net (79.151.49.6) a                                                                                                                         re filtered
Too many fingerprints match this host to give specific OS details
TCP/IP fingerprint:
SCAN(V=5.21%D=1/7%OT=%CT=%CU=%PV=N%DS=5%DC=T%G=N%TM=4D2769AD%P=i686-pc-linux-gnu                                                                                                                         )
U1(R=N)
IE(R=N)

Network Distance: 5 hops

TRACEROUTE (using proto 1/icmp)
HOP RTT       ADDRESS
1   0.89 ms   192.168.1.1
2   55.03 ms  192.168.153.1
3   55.47 ms  162.Red-81-46-53.staticIP.rima-tde.net (81.46.53.162)
4   88.06 ms  137.Red-81-46-55.staticIP.rima-tde.net (81.46.55.137)
5   151.29 ms 6.Red-79-151-49.dynamicIP.rima-tde.net (79.151.49.6)

Read data files from: /usr/local/share/nmap
OS and Service detection performed. Please report any incorrect results at http:                                                                                                                         //nmap.org/submit/ .
Nmap done: 1 IP address (1 host up) scanned in 211.73 seconds
           Raw packets sent: 2056 (93.996KB) | Rcvd: 11 (720B)

Alguna ayuda?

Ahora me funciona, pero es depende de la direccion que analice. En algunos casos la analiza bien y en otros pues no da resultados positivos. Pero lo que casi nunca logra averiguar es el SO. Dice: