H3C Technologies H3C S12500-X Series Switches - Manual (Page 17)

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keeps the LSP's digest, and purges the LSP from the network by advertising the LSP that has the
remaining lifetime set to 0.
• LSP refresh interval—When the remaining lifetime of a locally originated LSP is no greater than
(maximum age – refresh interval), the LSP is refreshed even if no change occurs to it. This
mechanism avoids frequent LSP aging and ensures network stability.
• Maximum length of an LSP originated by an RB—The actual maximum LSP length is determined by
the smallest of following values:
{
The configured value.
{
The interface MTU.
{
The maximum length of an LSP originated by an RB (which is carried in LSPs).
• Maximum length of an LSP that can be received by an RB—When the RB receives an LSP
exceeding the length, the RB drops the LSP.
• Overload bit of LSPs—When the Overload bit in the LSPs sent by an RB is set, 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 failed RB.
• Minimum LSP interval and maximum number of LSPs transmitted per time—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 time.
To prevent LSPs from being aged out accidentally, set the LSP maximum age and the LSP refresh
interval appropriately.
To adjust LSP-related 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.
5. Configure the
maximum length of an
LSP originated by an
RB.
lsp-length originate size
The default setting is 1458 bytes.
The maximum length of an LSP originated
by an RB cannot be greater than the
maximum length of an LSP that can be
received by an RB. Otherwise, the system
displays error messages.
6. Configure the
maximum length of an
LSP that can be
received by an RB.
lsp-length receive size
The default setting is 1492 bytes.
The maximum length of an LSP that can be
received by an RB cannot be smaller than
the maximum length of an LSP originated by
an RB. Otherwise, the system displays error
messages.