nmap scans, GFI NSS doesnt

[kabix]

got a question... i tried scanning one machine with nmap and it returned open ports (-P0). however, when i try to scan it with GFI NSS it says no machines found alive. whats the deal?

also is it serious problem if nmap returns these ports with -P0?:

PORT STATE SERVICE

25/tcp filtered smtp

42/tcp open nameserver

53/tcp open domain

80/tcp open http

88/tcp open kerberos-sec

110/tcp open pop3

135/tcp open msrpc

136/tcp filtered profile

137/tcp filtered netbios-ns

138/tcp filtered netbios-dgm

139/tcp filtered netbios-ssn

389/tcp open ldap

443/tcp open https

445/tcp filtered microsoft-ds

464/tcp open kpasswd5

593/tcp open http-rpc-epmap

636/tcp open ldapssl

691/tcp open resvc

995/tcp open pop3s

1026/tcp open LSA-or-nterm

1027/tcp open IIS

1378/tcp open elan

1723/tcp open pptp

1900/tcp open UPnP

1999/tcp open tcp-id-port

2000/tcp open callbook

3268/tcp open globalcatLDAP

3269/tcp open globalcatLDAPssl

3389/tcp open ms-term-serv

6001/tcp open X11:1

6002/tcp open X11:2

6004/tcp open X11:4

6101/tcp open VeritasBackupExec

6106/tcp open isdninfo

8000/tcp open http-alt

8082/tcp open blackice-alerts

10000/tcp open snet-sensor-mgmt

38292/tcp open landesk-cba

[+BudMan MVC]

"-P0 Don't ping hosts" so your not looking for ICMP echo before scanning.. but NSS most likely checks for ICMP echo before scanning.. what do you not understand?

[kabix]

ok. i get it.

what about the ports?

[+BudMan MVC]

I would hope that scan is from the LAN side of your network ;)