Configure OSPF GR

GR (Graceful Restart) is used to keep the route information of the forwarding layer between the local device and the neighbor device unchanged during the active/standby switchover of the devices and the forwarding is not affected. After switching the device and running again, the protocol layer of the two devices synchronizes the route information and updates the forwarding layer so that the data forwarding is not interrupted during the device switchover.

There are two roles during GR:

• GR Restarter: The device performing the protocol graceful restarting
• GR Helper: The device assisting the protocol graceful restarting

The distributed device can serve as GR Restarter and GR Helper, while the centralized device can only serve as GR Helper, assisting Restarter to complete GR.

Configuration Condition

Before configuring OSPF GR, first complete the following task:

• Configure the interface IP address, making the neighboring node available
• Enable the OSPF protocol

Configure OSPF GR Restarter

Table 7-36 Configure OSPF GR Restarter

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  The OSPF GR function can be used only in the stacking environment or dual-control environment.

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Configure OSPF GR Helper

GR Helper helps Restarter to complete GR. By default, the device enables the function. The nsf ietf helper disable command is used to disable the GR Helper function. The nsf ietf helper strict-lsa-checking command is used to configure Helper to perform the strict check for LSA during GR. If finding that the LSA does not change, exit the GR Helper mode.

Table 7-37 Configure OSPF GR Helper