Nmap Development mailing list archives
Re: -sP showing all hosts in request as up
From: David Fifield <david () bamsoftware com>
Date: Wed, 26 Aug 2009 10:35:19 -0600
On Wed, Aug 26, 2009 at 11:00:44AM -0500, Terry wrote:
On Wed, Aug 26, 2009 at 10:53 AM, David Fifield<david () bamsoftware com> wrote:Nmap has a lot of ways to find out if a host is up, and ICMP echo (ping) is just one of them. It's possible that Nmap finds a host up when ping finds it down. Those hosts above that say "echo-reply" got a ping reply. The ones that say "reset" got a RST from Nmap's ACK to port 80 or SYN to port 443. It is possible that there is a firewall or something spoofing the RST replies. If you're sure those addresses are not really up you can try looking for the device that's doing that.It's all internal and the firewall isn't logging anything special. I am sure they are down. I want the fastest way to determine if something is listening on an IP. This is all internal so I will ensure that this scanning host has full access to everything it is scanning.
If something is spoofing RSTs then one thing you can do is avoid sending probes that can get a RST. Nmap's default host discovery is -PE -PA80 -PS443 -PP Try removing the -PA and -PS that can get a RST, and use the options -PE -PP -PE on its own is the same as the ping program. Adding -PP (timestamp request) may find slightly more hosts). David Fifield _______________________________________________ Sent through the nmap-dev mailing list http://cgi.insecure.org/mailman/listinfo/nmap-dev Archived at http://SecLists.Org
Current thread:
- -sP showing all hosts in request as up Terry (Aug 26)
- Re: -sP showing all hosts in request as up David Fifield (Aug 26)
- Re: -sP showing all hosts in request as up Terry (Aug 26)
- Re: -sP showing all hosts in request as up David Fifield (Aug 26)
- Re: -sP showing all hosts in request as up Terry (Aug 26)
- Re: -sP showing all hosts in request as up David Fifield (Aug 26)
- Re: -sP showing all hosts in request as up Terry (Aug 26)
- Re: -sP showing all hosts in request as up David Fifield (Aug 26)