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Configuring the Switching Database Manager
Monitoring and Verifying the QoS Configuration
To verify the QoS configuration, perform the following tasks beginning in privileged EXEC mode:
Task
Step 1
Verify that QoS-based switching is enabled.
Step 2
Display effective mapping at either the system level
or interface level.
Step 3
Display the input port QoS parameters
Configuring the Switching Database Manager
This section describes the switching database manager (SDM) features supported on the Layer 3
Services module and how to configure them.
Overview of the SDM
Gigabit Ethernet interfaces use the forwarding engine and ternary content-addressable memory
(TCAM) to implement Layer 3 switching. The SDM is the Layer 3 software subsystem that manages
the Layer 3 switching information maintained in TCAM.
SDM in Layer 3 switching organizes the switching information in TCAM into protocol-specific regions
and configures the size of these protocol regions. SDM enables exact-match and longest-match address
searches, which result in high-speed forwarding.
The forwarding engine on the Gigabit Ethernet interfaces performs packet processing on multiple
channels simultaneously and extracts the packet header information. It uses this packet header
information to issue exact-match or longest-match address searches in the switching information stored
in TCAM.
TCAM identifies the location index of the Layer 2 or Layer 3 address and conveys it to the forwarding
engine. The forwarding engine uses this location index to derive information associated with each
Layer 2 and Layer 3 address.
SDM Regions
SDM partitions TCAM space into multiple protocol-specific regions and interacts with the individual
protocol control layers to store Layer 3 switching information. SDM consists of these two types of
regions:
•
•
Installation and Configuration Note for the Catalyst 4000 Layer 3 Services Module
74
Exact-match region—The exact-match region consists of Layer 3 entries for multiple protocol
regions, such as IP adjacencies and IPX node.
Longest-match region—Each longest-match region consists of multiple buckets or groups of Layer
3 address entries organized in decreasing order by mask length. All entries within a bucket share
the same mask value and key size. The buckets can change their size dynamically by borrowing
address entries from neighboring buckets.
Command
Router # show qos switching
Router # show qos mapping [destination
dest-interface]
Router # show epc port-qos interface interface
input
78-10164-03
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