R0106-HP MSR Router Series ACL and QoS Configuration Guide(V7)

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• 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 rules and their 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 1 lists the s
equence 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 cate
g
or
y
Se
q
uence of tie breakers
IPv4 basic ACL
1. VPN instance.
2. More 0s in the source IPv4 address wildcard (more 0s means a
narrower IPv4 address range).
3. Rule configured earlier.
IPv4 advanced ACL
4. VPN instance.
5. Specific protocol number.
6. More 0s in the source IPv4 address wildcard mask.
7. More 0s in the destination IPv4 address wildcard.
8. Narrower TCP/UDP service port number range.
9. Rule configured earlier.
IPv6 basic ACL
10. VPN instance.
11. Longer prefix for the source IPv6 address (a longer prefix means a
narrower IPv6 address range).
12. Rule configured earlier.
IPv6 advanced ACL
13. VPN instance.
14. Specific protocol number.
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. Rule configured earlier.
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. Rule configured earlier.
A wildcard mask, also called an inverse mask, is a 32-bit binary number represented in dotted decimal
notation. In contrast to a network mask, the 0 bits in a wildcard mask represent "do care" bits, and the
1 bits represent "don't care" bits. If the "do care" bits in an IP address are identical to the "do care" bits
in an IP address criterion, the IP address matches the criterion. All "don't care" bits are ignored. The 0s
and 1s in a wildcard mask can be noncontiguous. For example, 0.255.0.255 is a valid wildcard mask.
Rule numbering
ACL rules can be manually numbered or automatically numbered. This section describes how automatic
ACL rule numbering works.
Rule numbering step
If you do not assign an ID to the rule you are creating, the system automatically assigns it a rule ID. The
rule numbering step sets the increment by which the system automatically numbers rules. For example, the
default ACL rule numbering step is 5. If you do not assign IDs to rules you are creating, they are