I have the following (working) IPv4-only network situation

                    x.253/29   x.254/29  192.168/16
[The 'net] --- [Modem] --------- [NetBSD] -----------[LAN]
                                ne0      rtk0

The NetBSD (1.6RC1-i386 if that matters) box working as a NAT for the 
network. IP forwarding is enabled.

Since I have one more address available to my use (x.252) I'd like to 
have one of the boxes on the LAN (call that xxx) to have that address 
and skip NAT.

What I did was:
set up xxx to have as address x.252 and default gateway x.254
set up NetBSD box to have rtk0 alias x.254/29
route change x.252 -ifp rtk0 (for reachability)

Now I can happily ping between NetBSD and xxx, both on 192.168/16 and 
x/29 networks. But, as soon as I try something harder, like 'traceroute 
www.google.com', the first hop is OK (NetBSD box) but I get tons of * * 
*'s on the following hops. IOW, it does not go outside. Nothing is 
blocked by the firewall (which I tried to disable, too, with no change).

On the NetBSD box I have correct routes: route get www.google.com shows 
x.253 as the (right) gateway, and the traceroute goes fine. It works too 
if (from xxx) I use the 192.168 address (but this time is using NAT)

What's wrong? What can I do? Is there a better way?
Am I in the wrong place? `:)

Thank you for your attention.
	Paolo Torelli