Cant scan with nmap or nessus

saltas · 09-29-2004, 01:01 PM

The problem is that I can only use nmap or nessus to scan in my own net (192.168.0.1-255). When I do a nmap 200.254.***.*** its says that the server is down, but Im sure is not down (mozilla can reach it).

Anyone knows why is this?

Thanks.

dcostakos · 09-29-2004, 03:10 PM

My guess is that either the servers on the other subnet do not allow incoming ICMP traffic or network firewall rules block ICMP between subnets.

Try this:

Code:

nmap -P0 <IP_ADDR>

If it hangs for a while, the network firewall rules are probably also dropping packets for certain ports (probably most all of them). -- which would make a Nessus or nmap scan take forever.

To see if that's the case, try nmapping only a single port that you know is accessible -- like port 80:

Code:

nmap -p 80 -P0 <IP_ADDR>

saltas · 09-29-2004, 03:34 PM

Thanks, nmap -p 80 -P0 worked just fine.