93
•
The spanning tree feature is disabled on Device A and Device B and enabled on all devices in
user network 1 and user network 2.
•
The IRF fabric transparently transmits BPDUs for both user networks and is not involved in the
calculation of spanning trees.
When the network topology changes, it takes time for the IRF fabric to update its MAC address table
and ARP table. During this period, traffic in the network might be interrupted.
Figure 28 TC Snooping application scenario
To avoid traffic interruption, you can enable TC Snooping on the IRF fabric. After receiving a
TC-BPDU through a port, the IRF fabric updates MAC address table and ARP table entries
associated with the port's VLAN. In this way, TC Snooping prevents topology change from
interrupting traffic forwarding in the network. For more information about the MAC address table and
the ARP table, see "
Configuring the MAC address table
" and
Layer 3—IP Services Configuration
Guide
.
Configuration restrictions and guidelines
When you configure TC Snooping, follow these restrictions and guidelines:
•
TC Snooping and the spanning tree feature are mutually exclusive. You must globally disable
the spanning tree feature before enabling TC Snooping.
•
The priority of BPDU tunneling is higher than that of TC Snooping. When BPDU tunneling is
enabled on a port, the TC Snooping feature does not take effect on the port.
•
TC Snooping does not support the PVST mode.
Configuration procedure
To enable TC Snooping:
Step Command
Remarks
1.
Enter system view.
system-view
N/A
2.
Globally disable the spanning
tree feature.
undo stp global
enable
By default, the spanning tree feature is
disabled globally.
3.
Enable TC Snooping.
stp tc-snooping
By default, TC Snooping is disabled.
Summary of Contents for H3C S7500E-X
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