Configuring LSP Parameters

You can specify the following parameters for LSPs:

lsp-gen-interval

Use to set the minimum interval rate that LSPs are generated on a per-LSP basis.
You can set an interval value in the range 0–120 seconds.
The default interval value is 5 seconds. When a link is changing state at a high rate, the default value limits the signaling of the changing state to once every 5 seconds. Because the generation of an LSP may cause all routers in the area to perform the SPF calculation, controlling this interval can have an areawide effect.
When you raise this interval, you reduce the load on the network imposed by a rapidly changing link.
Example host1(config-router)#lsp-gen-interval level-2 30
Use the no version to restore the default value, 5.
See lsp-gen-interval

lsp-mtu

Use to specify the MTU LSP size in bytes. The size must be less than or equal to the smallest MTU of any link in the area.
Use this command to limit the size of LSPs generated by this router only. The router can receive LSPs of any size up to the maximum.
You can set the value in the range 128–9180.
The default LSP MTU value is 1497.
When a very large amount of information is generated by a single router, we recommend that you increase the LSP MTU. However, the default MTU is usually sufficient.
If the MTU of a link is lowered to less than 1500 bytes, the LSP MTU must be lowered accordingly on each router in the network. If this is not done, routing may become unpredictable.
Example host1(config-router)#lsp-mtu 1500
Use the no version to restore the default value, 1497.
See lsp-mtu

lsp-refresh-interval

Use to set the LSP rate at which locally generated LSPs are periodically transmitted.
The refresh interval determines the rate at which the router software periodically transmits the route topology information that it originates. These transmissions refresh the link-state information, reaffirming that the router is still up and that the link-state information in the LSP is still valid.
You can set the interval rate in the range 1–65535 seconds; the default is 900 seconds.
LSPs must be periodically refreshed before their lifetimes expire. The refresh interval must be less than the LSP lifetime specified by max-lsp-lifetime.
In the unlikely event that link stage database corruption is undetected, reducing the refresh interval reduces the amount of time that the corruption can persist.
Increasing the interval reduces the link utilization caused by the flooding of refreshed packets.
Example host1(config-router)#lsp-refresh-interval 1000
Use the no version to restore the default value, 900 seconds.
See lsp-refresh-interval

max-lsp-lifetime

Use to set the maximum time that LSPs persist without being refreshed.
You can select a maximum time in the range 1–65535 seconds.
The default value is 1200 seconds (20 minutes).
You might need to adjust the maximum LSP lifetime if you change the LSP refresh interval with the lsp-refresh-interval command. The maximum LSP lifetime must be greater than the LSP refresh interval.
Example host1(config-router)#max-lsp-lifetime 1500
Use the no version to restore the default value, 1200 seconds.
See max-lsp-lifetime