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

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To configure IS-IS NSR:
Ste
p
Command Remarks
1. Enter system view
system-view N/A
2. Enter IS-IS view.
isis [ process-id ] [ vpn-instance
vpn-instance-name ]
N/A
3. Enable IS-IS NSR.
non-stop-routing Disabled by default.
4. Set the NSR interval.
non-stop-routing interval
interval-value
0 seconds by default, that is, no NSR interval
is configured.
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.
You can either enable IS-IS FRR to calculate a backup next hop automatically, or designate a backup next
hop with a routing policy for routes matching specific criteria.
Configuration prerequisites
Before you configure IS-IS FRR, complete the following tasks:
• Configure network layer addresses for interfaces to make the neighboring nodes reachable at the
network layer.
• Enable IS-IS.
Configuration guidelines
• Do not use FRR and BFD at the same time. Otherwise, FRR might fail to take effect.
• The automatic backup next hop calculation of FRR and that of TE are mutually exclusive.
Configuring IS-IS FRR to automatically calculate a backup next hop
Ste
p
Command Remarks
1. Enter system view.
system-view N/A