H3C Technologies H3C WX3000E Series Wireless Switches - Manual (Page 9)

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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 the ease of identification. After creating an ACL
with a name, you can neither rename it nor delete its name.
For an Ethernet frame header ACL, the ACL number and name must be globally unique. For an IPv4 basic
or advanced ACLs, its ACL number and name must be unique among all IPv4 ACLs, and for an IPv6
basic or advanced ACL, among all IPv6 ACLs. You can assign an IPv4 ACL the same number and name
as an IPv6 ACL.
Match order
The rules in an ACL are sorted in a specific 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 approach, carefully check the rule content and order.
• auto—Sorts ACL rules in depth-first order. Depth-first ordering ensures that any subset of a rule is
always matched before the rule.
Table 1 lists the sequence of tie breakers that depth-first ordering
uses to sort rules for each type of ACL.
Table 1 Sort ACL rules in depth-first order
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 type rather than IP (IP represents any protocol over IP)
2. More 0s in the source IP address wildcard mask
3. More 0s in the destination IP address wildcard
4. Narrower TCP/UDP service port number range
5. Smaller rule ID
IPv6 basic ACL
1. Longer prefix for the source IP address (a longer prefix means a narrower IP
address range)
2. Smaller rule ID
IPv6 advanced ACL
1. Specific protocol type rather than IP (IP represents any protocol over IPv6)
2. Longer prefix for the source IPv6 address
3. Longer prefix for the destination IPv6 address
4. Narrower TCP/UDP service port number range
5. Smaller rule ID
Ethernet frame header ACL
1. More 1s in the source MAC address mask (more 1s means a smaller MAC
address)
2. More 1s in the destination MAC address mask
3. Smaller rule ID