# Using CIDR notation to enter the IPv6 ACL prefix length

CIDR (Classless Inter-Domain Routing) notation is used to specify ACL prefix lengths. The switch compares the address bits specified by a prefix length for an SA or DA in an ACE with the corresponding address bits in a packet being filtered by the ACE. If the designated bits in the ACE and in the packet have identical settings, the addresses match.

SA or DA used in an ACL with CIDR notation |
Resulting prefix length defining an address match |
Meaning |
---|---|---|

2530:0:a03:e102::/64 |
2530:0:a03:e102 |
The leftmost 64 bits must match. The remaining 64 bits are wildcards. |

2530:0:a03:e102:215::/80 |
2530:0:a03:e102:215 |
The leftmost 80 bits must match. The remaining 48 bits are wildcards. |

2530:0:a03:e102:215:60ff:fe7a:adc0/128 |
2530:0:a03:e102:215:60ff:fe7a:adc0 |
All 128 bits must match. This specifies a single host address. |

2001:db8:a03:e102:0:ab4:100::/112 |
2001:db8:a03:e102:0:ab4:100 |
The leftmost 112 bits must match. The remaining 16 bits are wildcards. |