H3C Technologies H3C S10500 Series Switches - Manual (Page 9)

1
ACL configuration
NOTE:
Unless otherwise stated, ACLs refer to both IPv4 and IPv6 ACLs throughout this document.
ACL overview
An access control list (ACL) is a set of rules (or permit or deny statements) for identifying traffic based on
criteria such as source IP address, destination IP address, and port number.
ACLs are primarily used for packet filtering. A packet filter drops packets that match a deny rule and
permits packets that match a permit rule. ACLs are also used by many modules, QoS and IP routing for
example, for traffic classification and identification.
ACL applications on the switch
An ACL is implemented in hardware or software, depending on the module that uses it. If the module, the
packet filter or QoS module for example, is implemented in hardware, the ACL is applied to hardware
to process traffic. If the module, the routing or user interface access control module (Telnet or SNMP) for
example, is implemented in software, the ACL is applied to software to process traffic.
The user interface access control module denies packets that do not match any ACL. Some modules, QoS
for example, ignore the permit or deny action in ACL rules and do not base their drop or forwarding
decisions on the action set in ACL rules. See the specified module for information about ACL application.
ACL categories
Category ACL number IP version Match criteria
IPv4 Source IPv4 address
Basic ACLs
2000 to
2999
IPv6 Source IPv6 address
IPv4
Source IPv4 address, destination IPv4 address, packet
priority, protocols over IPv4, and other Layer 3 and Layer 4
header fields
Advanced ACLs
3000 to
3999
IPv6
Source IPv6 address, destination IPv6 address, packet
priority, protocols over IPv6, and other Layer 3 and Layer 4
header fields
Ethernet frame
header ACLs 4000 to
4999 IPv4 and
IPv6 Layer 2 header fields, such as source and destination MAC
addresses, 802.1p priority, and link layer protocol type
ACL numbering and naming
Each ACL category has a unique range of ACL numbers. When creating an ACL, you must assign it a
number. In addition, you can assign the ACL a name for ease of identification. After creating an ACL with
a name, you cannot rename it or delete its name.