HP FlexNetwork NJ5000, Руководство пользователя

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Configuring ACLs
Unless otherwise stated, ACLs refer to both IPv4 and IPv6 ACLs throughout this document.
Grayed-out options on Web configuration pages cannot be configured.
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 essentially 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 widely used by many modules, for
example, QoS and IP routing, for traffic identification.
ACL categories
Category ACL number IP version Match criteria
Basic ACLs 2000 to 2999
IPv4 Source IPv4 address
IPv6 Source IPv6 address
Advanced ACLs 3000 to 3999
IPv4
Source/destination IPv4 address, protocol number,
and other Layer 3 and Layer 4 header fields
IPv6
Source/destination IPv6 address, protocol number,
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
Match order
The rules in an ACL are sorted in certain order. When a packet matches a rule, the device stops the
match process and performs the action defined in the rule. If an ACL contains overlapping or
conflicting rules, the matching result and action to take depend on the rule order.
The following ACL match orders are available:
•
Config
—Sorts ACL rules in ascending order of rule ID. A rule with a lower ID is matched before
a rule with a higher ID. If you use this method, check the rule content and order carefully.
•
Auto
—Sorts ACL rules in depth-first order. Depth-first ordering makes sure any subset of a rule
is always matched before the rule. Table 132 lists the sequence of tie breakers that depth-first
ordering uses to sort rules for each type of ACL.
Table 132 Depth-first match for ACLs
ACL category Sequence of tie breakers
IPv4 basic ACL
1.
More 0s in the source IP address wildcard (more 0s means a
narrower IP address range).
2.
Smaller rule ID.
IPv4 advanced ACL
1.
Specific protocol number.
2.
More 0s in the source IP address wildcard mask.
3.
More 0s in the destination IP address wildcard.