FreeBSD and NMAP

[Edwin Brown]

You could also just enable pf and have one scrub rule. 

/etc/rc.conf 

pf_enable="YES"                 # Set to YES to enable packet filter (pf)
pf_rules="/etc/pf.conf"         # rules definition file for pf
pf_program="/sbin/pfctl"        # where the pfctl program lives
pf_flags=""                     # additional flags for pfctl
pflog_enable="YES"              # Set to YES to enable packet filter logging
pflog_logfile="/var/log/pflog"  # where pflogd should store the logfile
pflog_program="/sbin/pflogd"    # where the pflogd program lives
pflog_flags=""                  # additional flags for pflogd

----------------------------------------------------------------------------------------------------------------------

/etc/pf.conf

scrub all no-df random-id reassemble tcp

----------------------------------------------------------------------------------------------------------------------

Best regards,

Edwin


On 4/19/05, Damian Gerow <dgerow at afflictions.org> wrote:
> Thus spake Dominic Marks (dom at helenmarks.co.uk) [19/04/05 07:18]:
> : On Tuesday 19 April 2005 12:11, pck wrote:
> : > Hi,
> : >
> : > How can i hide from nmap that my OS is FreeBSD? Is this possible?
> :
> : # sysctl -ad | grep random_id
> : net.inet.ip.random_id: Assign random ip_id values
> : # echo 'net.inet.ip.random_id=1' >> /etc/sysctl.conf
> 
> That doesn't hide the OS.  That just makes the IP ID field random.
> 
> One way to help:
> 
>     echo "net.inet.tcp.drop_synfin=1' >> /etc/sysctl.conf
> 
> (Note that you need the "options TCP_DROP SYNFIN" line in your kernel
> config.)
> 
> Other than that... randomize the packet fingerprint data.  I know there's
> been at least one daemon that did this on Linux, as well as a kernel patch
> that did the same.  But I'd ask: why?  You're doing a significant amount of
> work for very little in return.
> 
>   - Damian
> _______________________________________________
> freebsd-stable at freebsd.org mailing list
> http://lists.freebsd.org/mailman/listinfo/freebsd-stable
> To unsubscribe, send any mail to "freebsd-stable-unsubscribe at freebsd.org"
>