Nmap Development mailing list archives
Re: nmap sending encapsulated packets
From: "Mike Lude" <mlude () pacbell net>
Date: Wed, 02 Apr 2008 18:52:25 -0700
David-- Actually, I just fired up zenmap and took one of its canned scans ("operating system detection"), but just about everything I try ends up sending these encapsulated packets. I don't think that it's anything special that I'm doing. Let me know if I can help debug things. /Mike On 2 Apr 2008 at 18:51, David Fifield wrote: Date sent: Wed, 2 Apr 2008 18:51:24 -0600 From: David Fifield <david () bamsoftware com> To: nmap-dev () insecure org Subject: Re: nmap sending encapsulated packets
On Wed, Apr 02, 2008 at 06:51:28PM -0500, Kris Katterjohn wrote:-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Mike Lude wrote:Now with almost any scan I do (for example, nmap -T Aggressive -O -v 192.168.155.22) it says that it can't find the host, and when I add the suggested -PN parameter it lists all ports as filtered, even though I have a perfectly accessible webserver running on the host to be scanned. So, I break out wireshark to see what's going on, and trace what nmap is sending and what I am receiving at the host. Every single outgoing packet is encapsulated, with a protocol of 0xFF. Here's a hex dump of the first packet sent: 0000 9c f4 20 00 03 00 03 00 03 00 00 00 08 00 45 00 0010 00 3c 94 91 00 00 80 ff ed 8c c0 a8 9b 3d c0 a8 0020 9b 16 45 00 00 28 71 62 00 00 2c 06 65 c9 c0 a8 0030 9b 3d c0 a8 9b 16 d3 0d 00 50 79 f3 1a 0a 00 00 0040 42 ba 50 10 04 00 4a 1a 00 00 This matches exactly with what I see on the host being scanned.Hmm.. I don't know; hopefully somebody else on this list can say something definitive. Not just an unrecognized protocol, but if I'm not mistaken protocol 0xFF should never actually be sent over a network. I think the old hack (1980's) for sending raw IP packets w/headers involved patching the kernel and setting the socket() protocol field to 0xFF since it should never be used for anything.Wow, Kris, thanks for refreshing my memory. I've seen this before. I see it when I use --send-ip on Windows. Mike, are you using that option? Nmap prints a warning in that case. If you're not, it seems Nmap is acting as if you are, and we need to check it out. 255 is the numerical value of IPPROTO_RAW, which is usually a special code that means to create a raw socket. I guess when Microsoft disabled raw sockets they just stopped giving this code its magical meaning, so it's interpreted literally as 255. David Fifield _______________________________________________ Sent through the nmap-dev mailing list http://cgi.insecure.org/mailman/listinfo/nmap-dev Archived at http://SecLists.Org
_______________________________________________ Sent through the nmap-dev mailing list http://cgi.insecure.org/mailman/listinfo/nmap-dev Archived at http://SecLists.Org
Current thread:
- nmap sending encapsulated packets Mike Lude (Apr 02)
- Re: nmap sending encapsulated packets Kris Katterjohn (Apr 02)
- Re: nmap sending encapsulated packets David Fifield (Apr 02)
- Re: nmap sending encapsulated packets Mike Lude (Apr 02)
- Re: nmap sending encapsulated packets David Fifield (Apr 02)
- Re: nmap sending encapsulated packets Mike Lude (Apr 03)
- RE: nmap sending encapsulated packets Rob Nicholls (Apr 03)
- RE: nmap sending encapsulated packets Mike Lude (Apr 03)
- Re: nmap sending encapsulated packets David Fifield (Apr 02)
- Re: nmap sending encapsulated packets Kris Katterjohn (Apr 02)