Example 1
Address: 192.168.50.0 Subnet Mask: 255.255.255.0
Access-list 25 deny 192.168.50.0 0.0.0.255
Example 2
Address: 172.16.0.0 Subnet Mask: 255.255.0.0
Access-list 12 permit 172.16.0.0 0.0.255.255
Example 3
Address: 10.0.0.0 Subnet Mask: 255.0.0.0
Access-list 125 deny udp 10.0.0.0 0.255.255.255 any