Huawei quidway s7700 - Page 532

Preemption
Mode
Advantage Disadvantage
Preempt
ion
mode
Delayed
preempt
ion
Each time a fault is
rectified, the system
automatically completes
preemption and ensures
that the specified
interface is blocked.
l Related commands need to be used to
specify the delayed preemption mode in
advance. The preemption delay does not
have a default value, and therefore
related commands must be used to set
the preemption delay.
l After delayed preemption is configured
successfully, a fault needs to be
simulated to ensure that the specified
interface is blocked.
Manual
preempt
ion
Whether the specified
interface will be blocked
can be controlled
manually.
l The manual preemption mode needs to
be specified in advance.
l After related faults are rectified and the
preemption action is taken, manual
preemption does not take effect.
Manual preemption needs to be
configured so that the specified
interface is blocked after the next fault
is rectified. This increases the
maintenance workload.
The following conditions must be met to trigger preemption:
l The topology of the SEP segment must be normal.
l The primary edge interface or no-neighbor primary edge interface has been elected in the
SEP segment.
l The function of flexibly specifying a blocked interface is enabled on the device where the
primary edge interface or no-neighbor primary edge interface resides.
Do as follows on the Layer 2 switching device where the primary edge interface or the no-
neighbour primary edge interface is elected.
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:
preempt { manual | delay seconds }
The preemption mode is configured on the primary edge interface.
Quidway S7700 Smart Routing Switch
Configuration Guide - Ethernet 10 SEP Configuration
Issue 01 (2011-07-15) Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
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