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.
Information About OSPFv3 Fast Convergence: LSA and SPF Throttling
Fast Convergence: LSA and SPF Throttling
The OSPFv3 LSA and 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
Tuning LSA and SPF Timers for OSPFv3 Fast Convergence
To tune LSA and SPF timers for OSPFv3 fast convergence, perform this procedure:
SUMMARY STEPS
- enable
- configure terminal
- router ospfv3 [process-id ]
- timers lsa arrival milliseconds
- timers pacing flood milliseconds
- timers pacing lsa-group seconds
- timers pacing retransmission milliseconds
DETAILED STEPS
Command or Action | Purpose | |
---|---|---|
Step 1 |
enable Example:
|
Enables privileged EXEC mode. Enter your password if prompted. |
Step 2 |
configure terminal Example:
|
Enters global configuration mode. |
Step 3 |
router ospfv3 [process-id ] Example:
|
Enables OSPFv3 router configuration mode for the IPv4 or IPv6 address family. |
Step 4 |
timers lsa arrival milliseconds Example:
|
Sets the minimum interval at which the software accepts the same LSA from OSPFv3 neighbors. |
Step 5 |
timers pacing flood milliseconds Example:
|
Configures LSA flood packet pacing. |
Step 6 |
timers pacing lsa-group seconds Example:
|
Changes the interval at which OSPFv3 LSAs are collected into a group and refreshed, checksummed, or aged. |
Step 7 |
timers pacing retransmission milliseconds Example:
|
Configures LSA retransmission packet pacing in IPv4 OSPFv3. |
Configuring LSA and SPF Throttling for OSPFv3 Fast Convergence
To configure LSA and SPF throttling for OSPFv3 fast convergence, perform this procedure:
SUMMARY STEPS
- enable
- configure terminal
- ipv6 router ospf process-id
- timers throttle spf spf-start spf-hold spf-max-wait
- timers throttle lsa start-interval hold-interval max-interval
- timers lsa arrival milliseconds
- timers pacing flood milliseconds
DETAILED STEPS
Command or Action | Purpose | |
---|---|---|
Step 1 |
enable Example:
|
Enables privileged EXEC mode.
|
Step 2 |
configure terminal Example:
|
Enters global configuration mode. |
Step 3 |
ipv6 router ospf process-id Example:
|
Enables OSPFv3 router configuration mode. |
Step 4 |
timers throttle spf spf-start spf-hold spf-max-wait Example:
|
Turns on SPF throttling. |
Step 5 |
timers throttle lsa start-interval hold-interval max-interval Example:
|
Sets rate-limiting values for OSPFv3 LSA generation. |
Step 6 |
timers lsa arrival milliseconds Example:
|
Sets the minimum interval at which the software accepts the same LSA from OSPFv3 neighbors. |
Step 7 |
timers pacing flood milliseconds Example:
|
Configures LSA flood packet pacing. |
Configuration Examples for OSPFv3 Fast Convergence: LSA and SPF Throttling
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
Maximum wait time between two consecutive SPFs 10000 msecs
Minimum LSA interval 5 secs
Minimum LSA arrival 1000 msecs
Additional References
Related Documents
Related Topic |
Document Title |
---|---|
IPv6 addressing and connectivity |
IPv6 Configuration Guide |
OSPFv3 Fast Convergence: LSA and SPF Throttling |
OSPF Shortest Path First Throttling module |
Standards and RFCs
Standard/RFC |
Title |
---|---|
RFCs for IPv6 |
IPv6 RFCs |
Feature Information for OSPFv3 Fast Convergence: LSA and SPF Throttling
The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.
Releases |
Feature Information |
---|---|
Cisco IOS XE Fuji 16.8.1a |
The feature was introduced. |