HP 5920 series Configuration Manual page 30

NOTE:
ISIS-SPB requires acknowledgement for each LSP sent on a point-to-point circuit. ISIS-SPB will retransmit
an LSP at 5-second intervals until it receives an acknowledgement for the LSP. This retransmission interval
is not user configurable.
Configuring the LSP lifetime
The LSP lifetime specifies the maximum amount of time for an LSP to be retained in an LSDB.
SPBM nodes add a lifetime in each LSP they have advertised. If an SPBM node does not receive an
update for an LSP before its lifetime expires, the SPBM node removes the LSP from the LSDB.
To configure the maximum LSP lifetime:
Step
1. Enter system view.
2. Enter SPBM view.
3. Configure the maximum LSP
lifetime.
Tuning the LSP refresh interval and LSP generation timer
To prevent LSPs from age-out and synchronize LSDBs, ISIS-SPB performs periodic LSP update and
event-driven update.
LSP refresh interval—Sets the interval at which ISIS-SPB regularly regenerates an LSP, regardless of
•
whether any change has occurred to the LSP.
LSP generation timer—Sets the delay for ISIS-SPB to generate a new version of an LSP in response
•
to an LSP change. For example, an update occurs because of a change in adjacency, interface
metric value, system ID, or area address.
The LSP generation timer is an exponential generation timer. With this timer, ISIS-SPB quickly responds to
the first events for an LSP and then slows down to protect the CPU from frequent LSP generation.
The LSP generation timer value is derived from the following parameters:
minimum-interval—Minimum LSP generation interval.
•
incremental-interval—Base number for the incremental interval.
•
maximum-interval—Maximum LSP generation interval.
•
When the network is stable, the LSP generation timer is set to the minimum interval for each LSP
generation.
incremental-interval×2
interval is reached. If an event triggers LSP generation after the maximum interval is reached, the LSP
generation timer re-initiates with the minimum interval.
NOTE:
The network is considered unstable if the interval between consecutive LSP generation events is smaller
than two times the maximum interval.
To tune the LSP refresh interval and the LSP regeneration timer parameters:
Command
system-view
spbm
timer lsp-max-age seconds
When the network
n-2 (n is the number of generation times) for each LSP generation until the maximum
is unstable, the LSP
26
Remarks
N/A
N/A
The default maximum LSP lifetime
is 1200 seconds.
generation timer increments by