Cisco Systems 3750E manual 36-11, Policing and Marking Flowchart on SVIs

Chapter 36 Configuring QoS

Understanding QoS

When configuring policing on an SVI, you can create and configure a hierarchical policy map with these two levels:

•VLAN level—Create this primary level by configuring class maps and classes that specify the port trust state or set a new DSCP or IP precedence value in the packet. The VLAN-level policy map applies only to the VLAN in an SVI and does not support policers.

•Interface level—Create this secondary level by configuring class maps and classes that specify the individual policers on physical ports the belong to the SVI. The interface-level policy map only supports individual policers and does not support aggregate policers. You can configure different interface-level policy maps for each class defined in the VLAN-level policy map.

See the “Classifying, Policing, and Marking Traffic on SVIs by Using Hierarchical Policy Maps” section on page 36-55for an example of a hierarchical policy map.

Figure 36-5shows the policing and marking process when hierarchical policy maps on an SVI.

Figure 36-5 Policing and Marking Flowchart on SVIs

Start

Get the VLAN and

interface-level classification

results for the packet.

Is an interface-level policer				No
configured for this packet?
		Yes
				No
Check if the packet is in the
profile by querying the policer.
	Yes
		Pass
		through	Check out-of-profile action			Drop	Drop packet.
			configured for this policer.
					Mark
			Modify DSCP according to the
			policed-DSCP map. Generate
				a new QoS label.
								92355
		Done

	Catalyst 3750-E and 3560-E Switch Software Configuration Guide
OL-9775-02		36-11