Huawei AR530 series Configuration Manual page 326

Huawei AR530&AR550 Series Industrial Switch Routers
Configuration Guide - Ethernet Switching
After receiving a topology change notification from a lower-layer network, a device on the upper-
layer network sends TC packets to instruct other devices on the upper-layer network to clear
original MAC addresses and learn new MAC addresses after the topology of the lower-layer
network changes. This ensures uninterrupted traffic forwarding.
Procedure
Step 1 Run:
system-view
The system view is displayed.
Step 2 Run:
sep segment segment-id
A SEP segment is created and the view of the SEP segment is displayed.
Step 3 Run:
tc-notify { segment { segment-id1 [ to segment-id2 ] } &<1-10> | stp }
The topology change of the specified SEP segment is reported to another SEP segment or a
network running other ring protocols such as STP or RRPP.
By default, the topology change of a SEP segment is not reported.
----End
Follow-up Procedure
In the networking scenario where three or more SEP ring networks exist, when a topology change
notification is sent through multiple links, the upper-layer network will receive it multiple times.
This reduces packet processing efficiency on the upper-layer network. Therefore, topology
change notifications need to be suppressed. Suppressing topology change notifications frees the
upper-layer network from processing multiple duplicate packets and protects the devices in the
SEP segment against topology change notification attacks.
Run the tc-protection interval interval-value command in the SEP segment view to set the
interval for suppressing topology change notifications.
By default, the interval for suppressing topology change notifications is 2s, and three topology
change notifications with different source addresses are processed within 2s.
Issue 01 (2014-11-30)
NOTE
Currently, topology changes in a SEP segment can be reported to other SEP segments, STP networks.
NOTE
l In the networking scenario where three or more SEP ring networks exist, the tc-protection interval
interval-value command must be run. If this command is not run, the default interval for suppressing
topology change notifications is used.
l A longer interval ensures stable SEP operation but reduces convergence performance.
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