IP TTL does not get decreased with route-to/reply-to.
pf(4) policy routing(route-to/reply-to) does not decrease the ip TTL when forwarding packets.
This makes pfSense invisible on traceroutes. Not sure this can be considered a bug or a 'feature' but worth noting and having others comments.
The following link has all the details http://forum.pfsense.org/index.php/topic,28724.0.html
Updated by Jim Pingle about 13 years ago
I added an FAQ to cover this since it affects older versions as well:
If we did add that eventually, it would be nice to control that behavior via sysctl. People may want to use it either way.