HP 6400cl, Management Manual, Page: 452 / 664

Access Control Lists (ACLs) for the Series 3400cl and Series 6400cl Switches
Configuring and Assigning an ACL
■ Duplicate ACEs are allowed in an ACL. However, multiple instances
of an ACE have no effect on filtering because the first instance
preempts any subsequent duplicates. Also, duplicate entries unnec­
essarily consume additional resources on assigned ACLs.
For more information, refer to “Editing ACLs and Creating an ACL Offline” on
page 10-65.
Using CIDR Notation To Enter the ACL Mask
You can use CIDR (Classless Inter-Domain Routing) notation to enter ACL
masks. The switch interprets the bits specified with CIDR notation as the IP
address bits in an ACL and the corresponding IP address bits in a packet. The
switch then converts the mask to inverse notation for ACL use.
Table 10-8. Examples of CIDR Notation for Masks
IP Address Used In an ACL
with CIDR Notation
Resulting ACL Mask Meaning
18.38.240.125/15 0.1.255.255 The leftmost 15 bits must match; the
remaining bits are wildcards.
18.38.240.125/20 0.0.15.255 The leftmost 20 bits must match; the
remaining bits are wildcards.
18.38.240.125/21 0.0.7.255 The leftmost 21 bits must match; the
remaining bits are wildcards.
18.38.240.125/24 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.
10-42