Meters are used to define ingress rate-limiting and rate-shaping. Some platforms also support meters for egress traffic. The following sections provide information on meters for specific platforms.
The SummitStack and standalone switches use a single-rate meter to determine if ingress traffic is in-profile or out-of-profile.
On ExtremeSwitching X450-G2, X460-G2, X670-G2, X435, X440-G2, X465, X590, X620, X690, X695, X870 series switches, you can also use single-rate meters to determine if egress traffic is in-profile or out-of-profile.
When ACL meters are applied to a VLAN or to any, the rate limit is applied to each port group. To determine which ports are contained within a port group, use any of the following commands:
show access-list usage acl-range port port
show access-list usage acl-rule port port
show access-list usage acl-slice port port
The out-of-profile actions are drop, set the drop precedence, mark the dot1p, or mark the DSCP with configured value. Additionally, each meter has an associated out-of-profile counter that counts the number of packets that were above the committed-rate (and subject to the out-of-profile-action).
Prior to ExtremeXOS 21.1, when traffic exceeded the specified meter rate, the traffic could be marked with a user-specified diffserv code point. As of ExtremeXOS 21.1, this out-of-profile marking capability is enhanced to additionally include the option of marking the 802.1p value. The 802.1p value that is marked will be the outer 802.1p value in both VLAN and VMAN tagging scenarios. In the latter, the SVLAN's 802.1p value will be modified. Like the existing dscp out-of-profile meter action, this out-of-profile action will work on global and per-port meters.
On ExtremeSwitching series switches, the meters are a per-chip, per-slice resource (see ACLs for complete information.)
Note
If set-drop-precedence is used as a meter out-of-profile action, you should configure WRED on the egress port so that red packets marked by the meter are dropped in case of egress congestion.