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Match order – H3C Technologies H3C SR8800 User Manual

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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 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 approach, check the rule content and order carefully.

auto—Sorts ACL rules in depth-first order. Depth-first ordering guarantees 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.

NOTE:

The match order of user-defined ACLs can only be config.

Table 1 Sort ACL rules in depth-first order

ACL category Sequence of tie breakers

IPv4 basic ACL

1.

VPN instance

2.

More 0s in the source IP address wildcard (more 0s means a narrower IP
address range)

3.

Smaller rule ID

IPv4 advanced ACL

4.

VPN instance

5.

Specific protocol type rather than IP (IP represents any protocol over IP)

6.

More 0s in the source IP address wildcard mask

7.

More 0s in the destination IP address wildcard

8.

Narrower TCP/UDP service port number range

9.

Smaller ID

IPv6 basic ACL

10.

VPN instance

11.

Longer prefix for the source IP address (a longer prefix means a narrower IP
address range)

12.

Smaller ID

IPv6 advanced ACL

13.

VPN instance

14.

Specific protocol type rather than IP (IP represents any protocol over IPv6)

15.

Longer prefix for the source IPv6 address

16.

Longer prefix for the destination IPv6 address

17.

Narrower TCP/UDP service port number range

18.

Smaller ID

Ethernet frame header ACL

19.

More 1s in the source MAC address mask (more 1s means a smaller MAC
address)

20.

More 1s in the destination MAC address mask

21.

Smaller ID

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