Using CIDR notation to enter the IPv4 ACL mask

Use CIDR notation to enter ACL masks. The switch interprets the bits specified with CIDR notation as the address bits in an ACL and the corresponding address bits in a packet that must match. The switch then converts the mask to inverse notation for ACL use.

Examples of CIDR notation for masks

Address used in an ACL with CIDR notation

Resulting ACL mask

Meaning

10.38.240.125/15

0.1.255.255

The leftmost 15 bits must match; the remaining bits are wildcards.

10.38.240.125/20

0.0.15.255

The leftmost 20 bits must match; the remaining bits are wildcards.

10.38.240.125/21

0.0.7.255

The leftmost 21 bits must match; the remaining bits are wildcards.

10.38.240.125/24

0.0.0.255

The leftmost 24 bits must match; the remaining bits are wildcards.

18.38.240.125/32

0.0.0.0

All bits must match.