R3303-HP HSR6800 Routers Layer 3 - IP Routing Configuration Guide

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• GR helper—The neighbor of the GR restarter. It helps the GR restarter to complete the GR process.
To prevent service interruption after an active/standby MPU switchover in standalone mode or a global
active/standby MPU switchover in IRF mode, 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 MPU switchover or global active/standby MPU 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 called "GR helpers"). Then, the
GR restarter retrieves its adjacencies and LSDB with the help of the GR helpers.
IMPORTANT:
You cannot confi
g
ure OSPFv3 GR after confi
g
urin
g
OSPFv3 virtual links, because they are not supported
at the same time.
Configuring GR restarter
You can configure the GR restarter capability on a GR restarter.
To configure GR restarter:
Ste
p
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:
Ste
p
Command Remarks
1. Enter system view.
system-view N/A
2. Enter OSPFv3 view.
ospfv3 [ process-id ] N/A
3. Enable the GR helper
capability.
graceful-restart helper enable
Optional.
Enabled by default.
4. Enable strict LSA
checking.
graceful-restart helper
strict-lsa-checking
Optional.
Disabled by default.