System information

Configuring IS-IS
10-17
Displaying the Shortest Path First Log
Use the show isis spf-log command in Privileged EXEC mode to display how often
and why the router has run a full SPF calculation for the Level 1 and Level 2 IS-IS
router, as shown below:
MOT#show isis spf-log
Table 10-1 describes the show isis spf-log command output fields:
P P bit. Detects if Intermediate System is capable of area partition repair.
OL Overload bit. Determines if Intermediate System is congested.
Table 10-2 show isis spf-log Command Output Field Descriptions
Output Field Description
When The amount of time since a full SPF calculation took place
given in hours:minutes:seconds. The previous 20 calculations
are logged.
Duration Number of milliseconds to complete this SPF run. The elapsed time is
in actual clock time, not CPU time.
Nodes Number of routers and pseudonodes (LANs) that make up the
topology calculated in this SPF run.
Count Number of events that triggered this SPF run. When there is a topology
change, often multiple LSPs are received in a short time period. A
router waits 5 seconds before running a full SPF run, so it can include
all new information. This count denotes the number of events (such as
receiving new LSPs) that occurred while the router was waiting its 5
seconds before running full SPF.
Last trigger LSP Whenever a full SPF calculation is triggered by a new LSP, the LSP ID
is stored in the router.
Triggers Refer to Table 10-3 for a list of reasons that triggered a full SPF
calculation.
Table 10-1 show isis database Command Output Field Descriptions
Output Field Description