On Wednesday 31 December 2003 04:33, Rui Paulo wrote:
> From FreeBSD LINT kernel configuration:
>
> # IPSTEALTH enables code to support stealth forwarding (i.e.,
> forwarding
> # packets without touching the ttl).  This can be useful to
> hide firewalls
> # from traceroute and similar tools.

You can use ipf fastroute to get this behaviour.