Configuring Parameters Of An Is-Is Gr Session - Huawei Quidway NetEngine80E Configuration Manual

HUAWEI NetEngine80E/40E Router
Configuration Guide - IP Routing
The system view is displayed.
Step 2 Run:
isis [ process-id ]
The IS-IS view is displayed.
Step 3 Run:
graceful-restart
IS-IS GR is enabled.
By default, IS-IS GR is disabled.
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7.21.3 Configuring Parameters of an IS-IS GR Session

By setting Intermediate System to Intermediate System (IS-IS) graceful restart (GR) parameters,
you can avoid temporary black holes on the network.
Context
The router that starts for the first time does not maintain the forwarding status. If the router
restarts, the LSPs generated when the router runs last time may exist in the link state database
(LSDB) of other routers in the network.
The sequence number of an LSP fragment is reinitialized when the router starts. Therefore, the
router considers that the previously advertised LSP stored on other routers is newer than the LSP
generated locally after the router starts. This leads to the temporary black hole in the network,
which lasts until the normal LSDB synchronization process finishes. The router then regenerates
its LSPs and advertises the LSPs with the highest sequence number.
When this router starts, if the neighbor of the router suppresses the advertisement of the
adjacency until this router advertises the updated LSPs, the preceding case can therefore be
avoided.
Perform the following steps on the router that runs IS-IS:
Procedure
Step 1 Run:
system-view
The system view is displayed.
Step 2 Run:
isis [ process-id ]
The IS-IS view is displayed.
Step 3 Run:
graceful-restart no-impact-holdtime
The holdtime of an IS-IS neighbor is configured to remain unchanged in IS-IS GR mode.
Step 4 (Optional) Run:
Issue 02 (2014-09-30) Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
7 IS-IS Configuration
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