interface Ethernet0/0
ip address 172.16.18.1 255.255.255.0
no ip directed-broadcast
rate-limit input access-group 140 1000000 2000 0 conform-action set-prec-transmit 3 exceed-action set-prec-transmit 2
rate-limit input access-group 150 500000 1000 0 conform-action transmit exceed-action drop
ip access-list extended 140
permit ip any 172.16.0.0 0.0.0.255
ip access-list extended 150
deny ip any 172.16.0.0 0.0.255.255
permit ip any any
To take advantage of the TOS value, you should enable fair-queuing on the uplink interface.
You can use the rate-limit output command, but be careful where you use it. Move it as far upstream as you can so that you don't wasste your WAN bandwidth by moving a packet to a remote router, only to drop it there.
