Concept Guide

Version Description
9.2(0.0) Introduced on the MXL 10/40GbE Switch IO Module.
Usage Information
LSP throttling slows down the frequency at which LSPs are generated during network instability. Even though
throttling LSP generations slows down network convergence, no throttling can result in a network not functioning
as expected. If network topology is unstable, throttling slows down the scheduling of LSP generations until the
topology regains its stability.
The rst generation is controlled by the initial wait interval and the second generation is controlled by the second
wait interval. Each subsequent wait interval is twice as long as the previous one until the wait interval reaches the
maximum wait time specied (interval seconds). After the network calms down and there are no triggers for
two times the maximum interval, fast behavior is restored (the initial wait time).
lsp-mtu
Set the maximum transmission unit (MTU) of IS-IS link-state packets (LSPs). This command only limits the size of LSPs this router
generates.
Syntax
lsp-mtu size
To return to the default values, use the no lsp-mtu command.
Parameters
size The maximum LSP size, in bytes. The range is from 128 to 1497 for Non-Jumbo mode and
from 128 to 9195 for Jumbo mode. The default is 1497.
Defaults 1497 bytes.
Command Modes ROUTER ISIS
Supported Modes Full–Switch
Command History
Version Description
9.9(0.0) Introduced on the FN IOM.
9.2(0.0) Introduced on the MXL 10/40GbE Switch IO Module.
Usage Information
The link MTU and the LSP MTU size must be the same.
Because each device can generate a maximum of 255 LSPs, consider carefully whether you use the lsp-mtu
command.
lsp-refresh-interval
Set the link state PDU (LSP) refresh interval. LSPs must be refreshed before they expire. When the LSPs are not refreshed after a refresh
interval, they are kept in a database until their max-lsp-lifetime reaches zero and then LSPs is purged.
Syntax
lsp-refresh-interval seconds
To restore the default refresh interval, use the no lsp-refresh-interval command.
Intermediate System to Intermediate System (IS-IS) 795