H3C Technologies H3C S12500 Series Switches - Manual (Page 335)

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Configuring OSPFv3 GR
IMPORTANT:
You cannot configure OSPFv3 GR after configuring OSPFv3 virtual links, because they are not supported
at the same time.
Graceful Restart ensures the continuity of packet forwarding when a routing protocol restarts or an
active/standby switchover occurs:
• GR restarter—Graceful restarting router. It must be Graceful Restart capable.
• GR helper—The neighbor of the GR restarter. It helps the GR restarter to complete the GR process.
To prevent service interruption after a master/backup switchover, a GR restarter running OSPFv3 must
complete the following tasks:
• Keep the GR restarter forwarding entries stable during reboot.
• Establish all adjacencies and obtain complete topology information after reboot.
After the active/standby switchover, the GR restarter sends a Grace-LSA to tell its neighbors that it
performs a GR. Upon receiving the Grace-LSA, the neighbors with the GR helper capability enter the
helper mode (and are thus called GR helpers). Then, the GR restarter retrieves its adjacencies and LSDB
with the help of the GR helpers.
Configuring GR restarter
You can configure the GR restarter capability on a GR restarter.
To configure GR restarter:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enter OSPFv3 view. ospfv3 [ process-id ] N/A
3. Enable the GR
capability.
graceful-restart enable Disabled by default.
4. Configure the GR
interval. graceful-restart interval
interval-value
Optional.
120 seconds by default.
Configuring GR helper
You can configure the GR helper capability on a GR helper.
To configure GR helper:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enter OSPFv3 view. ospfv3 [ process-id ] N/A