# 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.

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. |