Using CIDR notation to enter the ACE mask

You can use Classless Inter-Domain Routing (CIDR) notation to enter ACE masks. The switch interprets the bits specified with CIDR notation as the IP address bits in an ACE and the corresponding IP address bits in a packet. The switch then converts the mask to inverse notation for ACE use.

CIDR notation for masks

IP 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.

10.38.240.125/32

0.0.0.0

All bits must match.