Rule Numbering - HP FlexNetwork MSR Series Configuration Manuals

Table 1 Sort ACL rules in depth-first order
ACL type
IPv4 basic ACL
IPv4 advanced ACL
IPv6 basic ACL
IPv6 advanced ACL
Layer 2 ACL
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 automatically numbered 0, 5, 10, 15, and so on. The wider the numbering step, the more
rules you can insert between two rules.
By introducing a gap between rules rather than contiguously numbering rules, you have the flexibility
of inserting rules in an ACL. This feature is important for a config-order ACL, where ACL rules are
matched in ascending order of rule ID.
Automatic rule numbering and renumbering
The ID automatically assigned to an ACL rule takes the nearest higher multiple of the numbering step
to the current highest rule ID, starting with 0.
Sequence of tie breakers
1. VPN instance.
2. More 0s in the source IPv4 address wildcard (more 0s means a
narrower IPv4 address range).
3. Rule configured earlier.
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.
10. VPN instance.
11. Longer prefix for the source IPv6 address (a longer prefix means a
narrower IPv6 address range).
12. Rule configured earlier.
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.
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.
7