Users Guide

OSPF route limit
OS10 supports up to 16,000 OSPF routes. Within this range, the only restriction is on intra-area routes that scale only up to
1000 routes. Other OSPF routes can scale up to 16 K.
Shortest path first throttling
Use shortest path first (SPF) throttling to delay SPF calculations during periods of network instability. In an OSPF network, a
topology change event triggers an SPF calculation that is performed after a start time. When the start timer finishes, a hold
time can delay the next SPF calculation for an additional time.
When the hold timer is running:
● Each time a topology change occurs, the SPF calculation delays for double the configured hold time up to maximum wait
time.
● If no topology change occurs, an SPF calculation is performed and the hold timer is reset to its configured value.
Set the start, hold, and wait timers according to the stability of the OSPF network topology. Enter the values in milliseconds
(ms). If you do not specify a start-time, hold-time, or max-wait value, the default values are used.
OSPFv2 and OSPFv3 instances support SPF throttling. By default, SPF timers are disabled in an OSPF instance. Enter the no
version of this command to remove the configured SPF timers and disable SPF throttling.
1. Configure an OSPF instance from CONFIGURATION mode, from 1 to 65535.
router {ospf | ospfv3} instance-number
2. Set OSPF throttling timers in OSPF INSTANCE mode.
timers spf [start-time [hold-time [max-wait]]]
● start-time — Configure the initial delay before performing an SPF calculation after a topology change, from 1 to
600000 milliseconds; default 1000.
● hold-time — Configure the additional delay before performing an SPF calculation when a new topology change
occurs, from 1 to 600000 milliseconds; default 10000.
● max-wait — Configure the maximum amount of hold time that can delay an SPF calculation, from 1 to 600000
milliseconds; default 10000.
Enable SPF throttling (OSPFv2)
OS10(config)# router ospf 100
OS10(config-router-ospf-100)# timers spf 1200 2300 3400
Layer 3
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