This is pointless ... as the user on the other side can increase their TTL value the same way you decreased it :-)
Not exactly.
If you use the "--ttl-dec" yes it would be sort of futile as the client on the other side could artificially inflate his / her TTL. HOWEVER if you use the "--ttl-set" then you could set the TTL to be what ever you want irregardless of what it was set to when it came in to your router.
Grant. . . .
