117Figure 30 TC Snooping application scenarioTo avoid traffic interruption, you can enable TC Snooping on the IRF fabric. After receiving a TC-BPDUthrough a port, the IRF fabric updates MAC address table and ARP table entries associated with theport's VLAN. In this way, TC Snooping prevents topology change from interrupting traffic forwarding inthe network. For more information about the MAC address table and the ARP table, see "Configuring theMAC address table" and Layer 3—IP Services Configuration Guide.Configuration restrictions and guidelinesWhen you configure TC Snooping, follow these restrictions and guidelines:• TC Snooping and the spanning tree feature are mutually exclusive. You must globally disable thespanning tree feature before enabling TC Snooping.• TC Snooping does not support the PVST mode.Configuration procedureTo enable TC Snooping:Step Command Remarks1. Enter system view. system-view N/A2. Globally disable thespanning tree feature. undo stp global enable• If the device starts up with the initialsettings, the spanning tree feature isdisabled globally by default.• If the device starts up with the factorydefaults, the spanning tree feature isenabled globally by default.For more information about the startupconfiguration, see FundamentalsConfiguration Guide.3. Enable TC Snooping. stp tc-snooping By default, TC Snooping is disabled.
