Changing packets ttl's
gizmen at zion.vsip.pl
Thu Apr 28 12:29:13 PDT 2005
> Do you mean the sysctl net.inet.ip.ttl?
No this sysctl is not what i want.
I need to change ttl of outgoing packets to my internal network.
For example. There is connection from host on internet.
it has for example 10 hops to my gateway. And when packet comes
to my box it has for example 55 ttl in ip header.
And then it is routed to host in my network so my box change ttl
to 54. But what i need is change ttl to '1'.
> On Wed, 27 Apr 2005, GiZmen wrote:
> > Hi,
> > I am searching how to change packet ttl. I am runing a freebsd 5.4
> > gateway and i would like to change ttl of any packets that are
> > going out from my internal interface. My goal is to change ttl to 1
> > so the last hop is the next host in my internal network.
> > I want to prevent people to do small NAT in my network. I know that
> > changing ttl's is easy to bypass but not for normal user :)
> > I am using pf as my packet filter but there is no option to change
> > ttls to smaler value. Please help me with this problem.
> > Big thanks
More information about the freebsd-net