ACL Allocation to Slices—ExtremeSwitching X870 Series Switches

ExtremeSwitching X870 series switches have four eight-port groups (known as pipes) that each have 6K of memory for a total switch capacity of 24K for ACLs. Key width (single, introslice double, double, and triple) is assigned automatically based on ACL rule size, and a single switch can contain ACLs with different key widths.

The ExtremeSwitching X870 series switches preferentially try to add subsequent rules to the current slice by automatically increasing the key width, if possible. For example, if the previous rule occupies a single-wide key space, and the subsequent rule can be added if the key width is changed to introslice double (or double, or triple), then the rule is added to the current slice group.

Unlike with other ExtremeSwitching switches, you cannot accurately determine by match conditions whether or not the subsequent rule can be added to the current slice due to the complex algorithm used by the ExtremeSwitching X870 series switches.

If you start to run out of ACL capacity, you can try to arrange rules by match conditions so as to optimize space. For example, if you have applied the following rules in the given order:
You can re-order the rules as:

The first set of rules occupies three slices, while the second occupies only two slices, resulting in more efficient use the TCAM space.