ACL Style Policy

Traditional ONEPolicy architecture uses a hierarchical approach to rule precedence where rule type dictates precedence. In addition, rule look-ups occur per role, per action type. This means, for example, that triggering a forward/drop rule without an explicit Class of Service (CoS) action results in applying the forward/drop action, and then continuing searching until a rule with CoS action matches. This hierarchical approach is implemented in hardware by maintaining one list for forward/drop actions, and one list for CoS actions. This implementation often results in underused resources, because not every rule has both forward/drop and CoS actions.

With ACL Style Policy, a mode of operation with a single ordered list per role is maintained. Rule look-ups occur in the provided ACL order per role. A match applies all actions specified, and the search stops. This approach can potentially double the advertised scale of classification rules as compared to the traditional model. It also provides a more standard approach to policy classification rules.

Default policy rule-model is hierarchical, unless you are upgrading from ExtremeXOS 30.5 with a saved configuration that is set to access list.

For information about configuring ACL Style Policy, see Configuring ACL Style Policy.

Limitations

SNMP for configuration of ACL Style Policy classification rules is not supported.

Traditional Versus ACL Style Policy Classification Rule Scaling

The following table compares the overall classification rule scale between "traditional" and ACL Style policy:

Table 1. Traditional Versus ACL Style Policy Classification Rule Scaling

Switch Model(s)	Traditional	ACL Style
X435	Default: 184 Less System ACL: 184	Default: 440 Less System ACL: N/A
X450-G2 X460-G2	Default: 952 Less System ACL: 1,464	Default: 3,000 Less System ACL: N/A
X670-G2 X870	Default: 952 Less System ACL: 952	Default: 1,976 Less System ACL: N/A
X440-G2 X620	Default: 440 Less System ACL: 440	Default: 952 Less System ACL: N/A
X690 X590 X465	Default: 1,976 Less System ACL: 1,976	Default: 4,024 Less System ACL: N/A
X695	Default: 1,976 Less System ACL: 1,976	Default: 3,512 Less System ACL: N/A
5420M	Default: 4,024 Less System ACL: 4.024	Default: 8,120 Less System ACL: N/A
5420F	Default: 1,976 Less System ACL: 1,976	Default: 4,024 Less System ACL: N/A
5520	Default: 4,024 Less System ACL: 4.024	Default: 8,120 Less System ACL: N/A

ACL Style Classification Rule Architecture

• Single ordered list per role.
• Rule look-ups done in provided ACL order.
• Rule look-up match applies all actions, and then the search stops.
• 5-tuple rule match support.
• Layer 4 port range.
• Rule types: application, ipsourcesocket, ipdestsocket, ipfrag, udpsourceportIP, udpdestportIP, tcpsourceportIP, tcpdestportIP, icmptype, icmp6type, ipttl, iptos, ipproto, ether.
• Rule actions: permit/deny, CoS (prio, tos, rate-limit, shape, etc), mirror, Syslog, and count.

RESTful API Support

ACL Style Policy implements a new RESTful API for configuration of classification rules.