Cisco OSPFv3 Fast Convergence: LSA and SPF Throttling Manual PDF

Tuning LSA and SPF Timers for OSPFv3 Fast Convergence

Configuring OSPFv3 Fast Convergence - LSA and SPF Throttling Information About OSPFv3 Fast Convergence: LSA and SPF Throttling, on page 1 How to Configure OSPFv3 Fast Convergence: LSA and SPF Throttling, on page 1 Example: Configuring LSA and SPF Throttling for OSPFv3 Fast Convergence, on page 3 Additional References, on page 4 Feature History for OSPFv3 Fast Convergence: LSA and SPF Throttling , on page 4 Information About OSPFv3 Fast Convergence:

LSA and SPF Throttling The Open Shortest Path First version 3 (OSPFv3) link-state advertisement (LSAs) and shortest-path first (SPF) throttling feature provides a dynamic mechanism to slow down link-state advertisement updates in OSPFv3 during times of network instability. It also allows faster OSPFv3 convergence by providing LSA rate limiting in milliseconds. OSPFv3 can use static timers for rate-limiting SPF calculation and LSA generation. Although these timers are configurable, the values used are specified in seconds, which poses a limitation on OSPFv3 convergence.

LSA and SPF throttling achieves subsecond convergence by providing a more sophisticated SPF and LSA rate-limiting mechanism that is able to react quickly to changes and also provide stability and protection during prolonged periods of instability. How to Configure OSPFv3 Fast Convergence: LSA and SPF Throttling The following sections provide configuration information about OSPFv3 Fast Convergence: LSA and SPF throttling. Tuning LSA and SPF Timers for OSPFv3 Fast Convergence To tune LSA and SPF timers for OSPFv3 fast convergence, perform this procedure: Configuring OSPFv3 Fast Convergence - LSA and SPF Throttling 1

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Configuring LSA and SPF Throttling for OSPFv3 Fast Convergence

Procedure Configuring LSA and SPF Throttling for OSPFv3 Fast Convergence To configure LSA and SPF throttling for OSPFv3 fast convergence, perform this procedure: Procedure Configuring OSPFv3 Fast Convergence - LSA and SPF Throttling Configuring LSA and SPF Throttling for OSPFv3 Fast Convergence Command or Action Purpose Step 1 enable Example: Device> enable Enables privileged EXEC mode. Enter your password if prompted. Step 2 configure terminal Example: Device# configure terminal Enters global configuration mode. Step 3 router ospfv3 [process-id] Example: Device(config)# router ospfv3 1 Enables OSPFv3 router configuration mode for the IPv4 or IPv6 address family.

Step 4 timers lsa arrival milliseconds Example: Device(config-rtr)# timers lsa arrival 300 Sets the minimum interval at which the software accepts the same LSA from OSPFv3 neighbors. Step 5 timers pacing flood milliseconds Example: Device(config-rtr)# timers pacing flood 30 Configures LSA flood packet pacing. Step 6 timers pacing lsa-group seconds Example: Device(config-router)# timers pacing lsa-group 300 Changes the interval at which OSPFv3 LSAs are collected into a group and refreshed, checksummed, or aged. Step 7 timers pacing retransmission milliseconds Example: Device(config-router)# timers pacing retransmission 100 Configures LSA retransmission packet pacing in IPv4 OSPFv3.

Command or Action Purpose Step 1 enable Example: Enables privileged EXEC mode. • Enter your password if prompted. Configuring OSPFv3 Fast Convergence - LSA and SPF Throttling 2

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Example: Configuring LSA and SPF Throttling for OSPFv3 Fast Convergence

Example: Configuring LSA and SPF Throttling for OSPFv3 Fast Convergence The following example show how to display the configuration values for SPF and LSA throttling timers: Device# show ipv6 ospf Routing Process "ospfv3 1" with ID 10.9.4.1 Event-log enabled, Maximum number of events: 1000, Mode: cyclic It is an autonomous system boundary router Redistributing External Routes from, ospf 2 Initial SPF schedule delay 5000 msecs Minimum hold time between two consecutive SPFs 10000 msecs Configuring OSPFv3 Fast Convergence - LSA and SPF Throttling Example: Configuring LSA and SPF Throttling for OSPFv3 Fast Convergence Command or Action Purpose Device> enable Step 2 configure terminal Example:

Device# configure terminal Enters global configuration mode. Step 3 ipv6 router ospf process-id Example: Device(config)# ipv6 router ospf 1 Enables OSPFv3 router configuration mode. Step 4 timers throttle spf spf-start spf-hold spf-max-wait Example: Device(config-rtr)# timers throttle spf 200 200 200 Turns on SPF throttling. Step 5 timers throttle lsa start-interval hold-interval max-interval Example: Device(config-rtr)# timers throttle lsa 300 300 300 Sets rate-limiting values for OSPFv3 LSA generation. Step 6 timers lsa arrival milliseconds Example: Device(config-rtr)# timers lsa arrival 300 Sets the minimum interval at which the software accepts the same LSA from OSPFv3 neighbors.

Step 7 timers pacing flood milliseconds Example: Device(config-rtr)# timers pacing flood 30 Configures LSA flood packet pacing. Configuring OSPFv3 Fast Convergence - LSA and SPF Throttling 3

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Feature History for OSPFv3 Fast Convergence: LSA and SPF Throttling

Maximum wait time between two consecutive SPFs 10000 msecs Minimum LSA interval 5 secs Minimum LSA arrival 1000 msecs Additional References Related Documents Standards and RFCs Feature History for OSPFv3 Fast Convergence: LSA and SPF Throttling This table provides release and related information for the features explained in this module. These features are available in all the releases subsequent to the one they were introduced in, unless noted otherwise. Use the Cisco Feature Navigator to find information about platform and software image support. To access Cisco Feature Navigator, go to https://cfnng.cisco.com/ .

Configuring OSPFv3 Fast Convergence - LSA and SPF Throttling Additional References Related Topic Document Title IPv6 addressing and connectivity IPv6 Configuration Guide OSPFv3 Fast Convergence: LSA and SPF Throttling OSPF Shortest Path First Throttling module Standard/RFC Title RFCs for IPv6 IPv6 RFCs Release Feature Feature Information Cisco IOS XE Gibraltar 16.11.1 OSPFv3 Fast Convergence - LSA and SPF Throttling The Open Shortest Path First version 3 (OSPFv3) LSAs and SPF throttling feature provides a dynamic mechanism to slow down link-state advertisement updates in OSPFv3 during times of network instability Configuring OSPFv3 Fast Convergence - LSA and SPF Throttling 4

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