$ route ADD 192.168.1.0 [color="red"]MASK[/color] [color="Red"]255.255.255.0[/color] 192.168.1.1
$ route ADD 192.168.1.0/24
gkontos said:If I may add, modifying routing tables to block certain networks is not a proper way.
You are not blocking any traffic this way. You are just fooling your gateway into sending packets somewhere else other than their proper destination.
Use PF, IPFW or any other packet filtering firewall for this.
George
/sbin/ifconfig disc0 create
/sbin/route add -net 1.2.3.0/24 -iface disc0