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topology Red
------------
Flags: T-System is on SPF TREE R-System is directly reachable
O-System is Overload D-System or Link is to be deleted
C-Neighbor is child P-Neighbor is parent
G-Cost gets greater L-Cost gets lower
H-Nexthop is changed U-Protocol usage is changed
V-Link is involved N-Link is a new path
S-Link is IGP Shortcut *-Relative cost
ISIS(1) Level-2 Shortest Path Tree
----------------------------------
SpfNode NodeFlags NeighbourNode LinkCost LinkFlags
------------------------------------------------------------------------
>0000.0000.0001.00 T/-/-/- 0000.0000.0003.01 10 C/-/-/-/-/-/-
0000.0000.0002.01 -/-/-/- 0000.0000.0002.00 0 -/-/-/-/-/-/-
>0000.0000.0001.00 0 -/-/-/-/-/-/-
0000.0000.0002.02 -/-/-/- 0000.0000.0002.00 0 -/-/-/-/-/-/-
0000.0000.0004.00 0 -/-/-/-/-/-/-
0000.0000.0003.00 T/-/-/- 0000.0000.0003.01 10 P/-/-/-/-/-/-
0000.0000.0003.02 10 C/-/-/-/-/-/-
0000.0000.0003.01 T/R/-/- 0000.0000.0003.00 0 C/-/-/-/-/-/-
>0000.0000.0001.00 0 P/-/-/-/-/-/-
0000.0000.0003.02 T/-/-/- 0000.0000.0003.00 0 P/-/-/-/-/-/-
0000.0000.0004.00 0 C/-/-/-/-/-/-
0000.0000.0004.00 T/-/-/- 0000.0000.0003.02 10 P/-/-/-/-/-/-
7.11 Configuring IPv4 IS-IS Auto FRR
With IS-IS Auto FRR, traffic on a faulty link can be quickly switched to the backup link of the
faulty link. This ensures that the traffic interruption time is within 50 ms and improves the
reliability of IS-IS networks.
7.11.1 Before You Start
Before configuring IS-IS Auto FRR, familiarize yourself with the usage scenario, complete the
pre-configuration tasks, and obtain the required data. This can help you complete the
configuration task quickly and accurately.
Applicable Environment
At present, the VoIP and on-line video services require high-quality real-time transmission.
Nevertheless, if an IS-IS fault occurs, multiple processes, including fault detection, LSP update,
LSP flooding, route calculation, and FIB entry delivery, must be performed to switch the traffic
to a new link. As a result, it takes much more than 50 ms to recover the link from the fault, which
cannot meet the requirement for real-time services on the network.
IS-IS Auto FRR ensures fast switchover of traffic to the backup link before the network
convergence, avoiding traffic interruption. This protects traffic and improves reliability of an
IS-IS network. The NE80E/40E supports IPv4 IS-IS Auto FRR.
IS-IS Auto FRR is suitable for IP services that require a low delay and low packet loss ratio.
Pre-configuration Tasks
Before configuring IS-IS Auto FRR, complete the following tasks:
HUAWEI NetEngine80E/40E Router
Configuration Guide - IP Routing
7 IS-IS Configuration
Issue 02 (2014-09-30)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
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