Blocking IP Address Ranges in CIDR
IP Address Ranges;
000.000.000.000 - 000.255.255.255 (reserved)
001.000.000.000 - 192.167.255.255
192.168.000.000 (the next number which is the first private IP Address #)
192.168.255.255 (the last number in the private IP Address range)
192.169.000.000 - 255.255.255.254
255.255.255.255 - 255.255.255.255 (reserved)
Same as above, but expressed in CIDR;
1.0.0.0/8
2.0.0.0/7
4.0.0.0/6
8.0.0.0/5
16.0.0.0/4
32.0.0.0/3
64.0.0.0/2
129.0.0.0/8
130.0.0.0/7
132.0.0.0/6
136.0.0.0/5
144.0.0.0/4
160.0.0.0/3
192.0.0.0/9
192.128.0.0/11
192.160.0.0/13
192.169.0.0/16
192.170.0.0/15
192.172.0.0/14
192.176.0.0/12
192.192.0.0/10
193.0.0.0/8
194.0.0.0/7
196.0.0.0/6
200.0.0.0/5
208.0.0.0/4
224.0.0.0/4
240.0.0.0/5
248.0.0.0/6
252.0.0.0/7
254.0.0.0/8
255.0.0.0/9
255.128.0.0/10
255.192.0.0/11
255.224.0.0/12
255.240.0.0/13
255.248.0.0/14
255.252.0.0/15
255.254.0.0/16
255.255.0.0/17
255.255.128.0/18
255.255.192.0/19
255.255.224.0/20
255.255.240.0/21
255.255.248.0/22
255.255.252.0/23
255.255.254.0/24
255.255.255.0/25
255.255.255.128/26
255.255.255.192/27
255.255.255.224/28
255.255.255.240/29
255.255.255.248/30
255.255.255.252/31
References;
https://en.wikipedia.org/wiki/Reserved_IP_addresses
https://ip2cidr.com/
...and if you really need it: https://www.ipaddressguide.com/cidr