Etherchannel with QoS Feature Evolution
An Etherchannel is a port-channel architecture that allows grouping of several physical links to create one logical Ethernet link for the purpose of providing fault tolerance, and high-speed links between switches, routers, and servers. An Etherchannel can be created from between two and eight active Fast, Gigabit, or 10-Gigabit Ethernet ports, with an additional one to eight inactive (failover) ports, which become active as the other active ports fail.
QoS for Etherchannel interfaces has evolved over several Cisco IOS XE releases. It is important to understand what level of support is allowed for your current level of Cisco IOS XE software and underlying Etherchannel configuration. Various combinations of QoS are supported based on how Etherchannel is configured. There are three different modes in which Etherchannel can be configured:
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Etherchannel VLAN-based load balancing via port-channel subinterface encapsulation CLI
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Etherchannel Active/Standby with LACP (no Etherchannel load balancing)
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Etherchannel with LACP with load balancing
Each of these models has specific restrictions regarding which levels of Cisco IOS XE software include support and the possible QoS configurations with each.
The following summarizes the various Etherchannel and QoS configuration combinations that are supported. Example configurations will be provided later in this document. Unless specifically mentioned together, the combination of service policies in different logical and physical interfaces for a given Etherchannel configuration is not supported.
Etherchannel VLAN-Based Load Balancing via Port-Channel Subinterface Encapsulation CLI
Supported in Cisco IOS XE Release 2.1 or later:
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Egress MQC Queuing Configuration on Port-Channel Subinterface
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Egress MQC Queuing Configuration on Port-Channel Member Link
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QoS Policies Aggregation—Egress MQC Queuing at Subinterface
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Ingress Policing and Marking on Port-Channel Subinterface
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Egress Policing and Marking on Port-Channel Member Link
Supported in Cisco IOS XE Release 2.6 or later:
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QoS Policies Aggregation—MQC Support for Multiple Queue Aggregation at Main Interface - Egress MQC Queuing at Main Interface
Etherchannel Active/Standby with LACP (No Etherchannel Load Balancing)
Supported in Cisco IOS XE 2.4 or later:
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Egress MQC Queuing on Port-Channel Member Link—No Etherchannel Load Balancing
Etherchannel with LACP and Load Balancing
Supported in Cisco IOS XE 2.5 or later:
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Egress MQC Queuing Configuration on Port-Channel Member Link—Etherchannel Load Balancing
Supported in Cisco IOS XE 3.12 or later:
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General MQC QoS support on Port-channel main-interface
We recommend that as a best practice for QoS, that you use port-channel aggregation—see the "Aggregate EtherChannel Quality of Service" chapter.
Supported in Cisco IOS XE 3.16.3 or later and in Cisco IOS XE Fuji 16.3 or later:
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General MQC QoS support on Port-channel sub-interface
We recommend that as a best practice for QoS, that you use port-channel aggregation—see the "Aggregate EtherChannel Quality of Service" chapter.