Configuring Is-Is Nsr; Configuring Is-Is Frr - HPE 5800 Series Configuration Manual

Step
Suppress the SA bit
5.
during restart

Configuring IS-IS NSR

According to the GR feature, after a master/slave switchover, the GR Restarter obtains routing
information from its neighbors, and the IS-IS process must learn all routes. If the network topology
has changed during the switchover period, removed routes cannot be updated to the device, which
may cause black hole routes.
NSR solves the problem by backing up IS-IS link state information from the master device to the
slave device. After a master/slave switchover, NSR can complete link state recovery and route
regeneration without requiring the cooperation of other devices.
The IS-IS NSR and IS-IS GR features are mutually exclusive.
To configure IS-IS NSR:
Step
Enter system view
1.
Enter IS-IS view.
2.
Enable IS-IS NSR.
3.
Set the NSR interval
4.

Configuring IS-IS FRR

When a link fails, the packets on the path are discarded, and a routing loop might occur until IS-IS
completes the routing convergence based on the new network topology.
You can enable IS-IS fast reroute (FRR) to reduce traffic recovery time.
Figure 48 Network diagram for IS-IS FRR
In Figure 48, after you enable FRR on Router B, IS-IS automatically calculates or designates a
backup next hop when a link failure is detected. In this way, packets are directed to the backup next
hop to reduce traffic recovery time. Meanwhile, IS-IS calculates the shortest path based on the new
network topology, and forwards packets over the path after network convergence.
Command
graceful-restart suppress-sa
Command
system-view
isis [ process-id ] [ vpn-instance
vpn-instance-name ]
non-stop-routing
non-stop-routing interval
interval-value
141
Remarks
Optional.
By default, the SA bit is not suppressed.
By enabling the GR Restarter to suppress
the Suppress-Advertisement (SA) bit in the
hello PDUs, the neighbors will still
advertise their adjacency with the GR
Restarter.
Remarks
N/A
N/A
Disabled by default.
0 seconds by default, that is, no NSR
interval is configured.