Cisco router ACL wildcard

Cisco router ACL wildcard

192.168.1.20-192.168.1.50 range of networks

A contiguous address, the form of a wildcard mask must be:

11111111=255

01111111=127

00111111=63

00011111=31

00001111=15

00000111=7

00000011=3

00000001=1

For range 20-50, be sure to use Access-list 1 per 192.168.1.0 0.0.0.63, then go head to tail

0-16 the maximum block address that can be contained is 16:access-list 1 deny 192.168.1.0 0.0.0.15

16-19 The maximum address block that can be contained is 4:access-list 1 deny 192.168.1.16 0.0.0.3

56-63 the maximum block address that can be contained is 8:access-list 1 deny 192.168.1.56 0.0.0.7

52-55 the maximum block address that can be contained is 4:access-list 1 deny 192.168.1.52 0.0.0.3

Only 511 addresses left: Access-list 1 deny host 192.168.1.51

The entire ACL is written as:

Access-list 1 Deny 192.168.1.0 0.0.0.15

Access-list 1 Deny 192.168.1.16 0.0.0.3

Access-list 1 Deny 192.168.1.56 0.0.0.7

Access-list 1 Deny 192.168.1.52 0.0.0.3

Access-list 1 Deny host 192.168.1.51

Access-list 1 per 192.168.1.0 0.0.0.63

Cisco router ACL wildcard