H3C Technologies H3C S6800 Series Switches - Manual (Page 21)

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• LSP maximum age—The RB uses the LSP maximum age as the remaining lifetime of the LSPs that it
originates. When the RB detects that the remaining lifetime of an LSP reaches 0 seconds in the LSDB,
the RB performs the following tasks:
{
Removes the LSP's content.
{
Keeps the LSP's digest.
{
Sets the LSP's remaining lifetime to 0 and purges the LSP from the network by advertising the LSP
to other RBs.
• LSP refresh interval—A locally originated LSP is forcibly refreshed when its remaining lifetime is no
greater than n: n = LSP maximum age – LSP refresh interval. This mechanism avoids frequent LSP
aging and ensures network stability.
• LSP generation timer parameters—By adjusting the TRILL LSP generation timer parameters, you can
prevent frequent network changes from consuming an excessive amount of bandwidth and device
resources.
When the network is stable, the LSP generation timer is set to the minimum interval for each LSP
generation. When the network is unstable, the LSP generation timer is added by the incremental
interval for each LSP generation until the maximum interval is reached.
• Maximum length of originated LSPs—The RB selects the smallest value from the following values as
the actual maximum length of LSPs to be sent to a neighbor:
{
The configured maximum length of originated LSPs.
{
The interface MTU.
{
The maximum originated LSP length carried in the LSPs sent by the neighbor.
• Maximum length of received LSPs—When the RB receives an LSP that exceeds the length, the RB
drops the LSP.
• Overload bit of LSPs—The RB sets the Overload bit in LSPs if the RB fails and cannot correctly
perform route selection and packet forwarding. When the RB cannot record the complete LSDB
because of insufficient memory, routing calculation errors occur. To make troubleshooting easier,
temporarily exclude the RB from the TRILL network by setting the Overload bit for the LSPs sent by the
RB.
• Minimum LSP interval and maximum number of LSPs transmitted per interval—To avoid frequent
LSP aging in the network, RBs periodically advertise LSPs. The actual refresh interval of an LSP is
determined by both the minimum LSP interval and the maximum number of LSPs transmitted per
interval. To prevent LSPs from being aged out accidentally, set the LSP maximum age and the LSP
refresh interval appropriately.
To set TRILL LSP parameters:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enter TRILL view. trill N/A
3. Set the LSP maximum
age.
timer lsp-max-age time The default setting is 1200 seconds.
4. Set the LSP refresh
interval.
timer lsp-refresh time The default setting is 900 seconds.