Default System Classes; Policy Types - Cisco AP775A - Nexus Converged Network Switch 5010 Configuration Manual

Information About QoS
the switch distributes the system class parameter values to all its attached network adapters using the Data
Center Bridging Exchange (DCBX) protocol.
If service policies are configured at the interface level, the interface-level policy always takes precedence
over system class configuration or defaults.
On the Cisco Nexus 5000 Series switch, a system class is uniquely identified by a qos-group value. A total
of six system classes are supported. Two of the six system classes are defaults and are always present on the
switch. Up to four additional system classes can be created by the administrator.

Default System Classes

The Cisco Nexus 5000 Series switch provides the following default system classes:
• Drop system class
• FCoE system class

Policy Types

The Cisco Nexus 5000 Series switch supports a number of policy types. You create class maps in the policy
types.
There are three policy types. The following QoS parameters can be specified for each type of class:
• Type network-qos—A network-qos policy is used to instantiate system classes and associate parameters
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By default, the software classifies all unicast and multicast Ethernet traffic into the default drop system
class. This class is identified by qos-group 0.
This class is created automatically when the system starts up (the class is named class-default in the
CLI). You cannot delete this class and you cannot change the match criteria associated with the default
class.
All Fibre Channel and FCoE control and data traffic is automatically classified into the FCoE system
class, which provides no-drop service.
This class is created automatically when the system starts up (the class is named class-fcoe in the CLI).
You cannot delete this class, and you can only modify the IEEE 802.1p CoS value to associate with this
class. This class is identified by qos-group 1.
The switch classifies packets into the FCoE system class as follows:
◦ FCoE traffic is classified based on EtherType.
◦ Native Fibre Channel traffic is classified based on the physical interface type.
The optional N5K-M1404 or N5K-M1008 expansion modules provide native
Note
1/2/4-Gigabit Fibre Channel ports.
with those classes that are of system-wide scope.
◦ Classification—The traffic that matches this class are as follows:
◦ QoS Group—A class-map of type network-qos identifies a system-class and is matched by
its associated qos-group.
Cisco Nexus 5000 Series Switch CLI Software Configuration Guide
Default System Classes
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