Re: help regarding IP address spoofing (when using nmap)

On Thursday, February 2, 2023 8:38:46 AM CST Sambuddho Chakravarty wrote:
> It was running as root only...
> 
> Also, no the address didn't belong to the interface,  and I was spoofing
> it...
> 
> So is there no way to spoof packet IP addresses ?

I don't know how nmap spoofs an IP, but in a pinch you could alias the IP you 
want first, run your scan, then drop the alias.

--Joey Kelly

> 
> On Thu, 2 Feb 2023, 18:59 J. Hellenthal, <jhellenthal@dataix.net> wrote:
> > On Thu, Feb 02, 2023 at 04:19:57PM +0530, Sambuddho Chakravarty wrote:
> > >    Hi All
> > >    
> > >     I am a relatively newbie to FreeBSD (earlier was running
> > >    
> > >    Linux). I am running FreeBSD 13.1.
> > >    I am trying to run nmap with source IP address spoofing
> > >    (for some academic purposes). It works fine with Linux
> > >    but on FreeBSD I get the following error:
> > >    # nmap -e re0 -S 192.168.17.92 -sS 143.110.249.18  -p 8080 -Pn
> > >    Starting Nmap 7.93 ( https://nmap.org ) at 2023-02-02 16:04 IST
> > >    NSOCK ERROR [0.0170s] mksock_bind_addr(): Bind to 192.168.17.92:0
> > 
> > failed
> > 
> > >    (IOD #1): Can't assign requested address (49)
> > >    NSOCK ERROR [0.0170s] mksock_bind_addr(): Bind to 192.168.17.92:0
> > 
> > failed
> > 
> > >    (IOD #2): Can't assign requested address (49)
> > >    It works fine without the source spoofing but doesn't when I use
> > >    it. I can however use my own machine's source IP address with
> > >    the '-S' option.
> > >    --
> > >    best,
> > >    sambuddho
> > 
> > sudo(8) or su(1) ?
> > 
> > An address should also be assigned to a interface for it to be bound to.
> > 
> > --
> > The fact that there's a Highway to Hell but only a Stairway to Heaven says
> > a lot about anticipated traffic volume.


-- 
Joey Kelly
Minister of the Gospel and Linux Consultant
http://joeykelly.net
504-239-6550