Displays IS-IS link-state packet (LSP) logging information.
Privileged EXEC mode
IS-IS is supported only on devices based on the DNX chipset family. For a list of such devices, see "Supported Hardware".
The show isis spf-log command displays the following information:
|  
					  Output field  |  
				   
					  Description  |  
				
|---|---|
|  
					  When  |  
				   
					  When (in hours: minutes : seconds) a full SPF calculation occurred. The last 20 occurrences are logged.  |  
				
|  
					  Duration  |  
				   
					  The time required to complete this SPF run, Elapsed time is normal clock time (not CPU time). Other options for this field are: 
  |  
				
|  
					  Nodes  |  
				   
					  The number of routers and pseudonodes (LANs) that make up the topology calculated in this SPF run.  |  
				
|  
					  Count  |  
				   
					  The number of events that triggered this SPF run. When a topology change has occurred, multiple link-state packets (LSPs) are received in a short time. Since a router waits about 5 seconds before running a full SPF run, it can include all new information. This count includes the number of events (such as receiving new LSPs) that occurred while the router was waiting the 5 second interval before running full SPF.  |  
				
|  
					  Last Trigger LSP  |  
				   
					  When a full SPF calculation is triggered by the arrival of a new LSP, the router stores the LSP ID. The LSP ID can provide a clue about the source of routing instability in an area. If multiple LSPs in a single level are causing SPF runs, only the LSP ID of the last received LSP is recorded.  |  
				
|  
					  Triggers  |  
				   
					  The reason that a full SPF calculations was triggered.  |  
				
|  
					  Alternate Route Check  |  
				   
					  PSPF deleted an IPv4 or IPv6 route. Full SPF must run to find the alternate route.  |  
				
|  
					  Route Change in L1 SPF Run  |  
				   
					  The L1 SPF run added or deleted an IPv4 or IPv6 route. The L2 SPF must run to accommodate this change.  |  
				
|  
					  LSP Purged  |  
				   
					  An LSP was purged. A full SPF calculation must process this change.  |  
				
|  
					  LSP Added  |  
				   
					  A new LSP has appeared in the database. A full SPF calculation is needed to process this new LSP.  |  
				
|  
					  Summary Address Change  |  
				   
					  A summary address configuration change has occurred.  |  
				
|  
					  Adjacency State Change  |  
				   
					  An adjacency was added or deleted.  |  
				
|  
					  Admin Distance Change  |  
				   
					  The administrative distance configuration has changed.  |  
				
|  
					  LSP Header Change  |  
				   
					  The LSP header (attached or overload bits) is changed.  |  
				
|  
					  IS Neighbor TLV Change  |  
				   
					  An IS neighbor TLV was added or deleted in an LSP.  |  
				
|  
					  Area Address TLV Change  |  
				   
					  The area address TLV changed.  |  
				
|  
					  Interface IP Address Change  |  
				   
					  The IP address configuration changed.  |  
				
|  
					  IP Address TLV Change  |  
				   
					  An IP address TLV changed in the LSP.  |  
				
|  
					  IPv6 Address TLV Change  |  
				   
					  An IPv6 address TLV changed in the LSP.  |  
				
|  
					  IS-IS Level Change  |  
				   
					  The IS-IS level configuration changed.  |  
				
|  
					  Interface Metric Change  |  
				   
					  The IS-IS interface metric configuration changed.  |  
				
|  
					  LSP Changed - PSPF Disabled  |  
				   
					  The LSP changed and PSPF is disabled.  |  
				
|  
					  LSP Overload Bit Change  |  
				   
					  The overload bit in the LSP header changed.  |  
				
|  
					  Interface State Change  |  
				   
					  The interface state changed to up or down.  |  
				
|  
					  Redist Prefix-List Change  |  
				   
					  The redistribution list configuration changed.  |  
				
|  
					  Redist Policy Change  |  
				   
					  The redistribution policy configuration changed.  |  
				
|  
					  Maximum Path Change  |  
				   
					  The IS-IS maximum path configuration changed.  |  
				
|  
					  IP Load Sharing Change  |  
				   
					  The IP load sharing configuration changed.  |  
				
|  
					  User Cleared IS-IS Route  |  
				   
					  The user cleared a specific IS-IS route.  |  
				
|  
					  User Cleared IS-IS Routes  |  
				   
					  The user cleared all IS-IS routes.  |  
				
|  
					  Neighbor NLPID Change  |  
				   
					  NLPID set is changed in received hellos.  |  
				
|  
					  ISIS Enable  |  
				   
					  IS-IS was enabled.  |  
				
|  
					  ISTCT_SPF Computation  |  
				   
					  The user issued the disable-incremental-stct-spf-opt command.  |  
				
|  
					  User Cleared IS-IS All  |  
				   
					  The user issued the clear isis all command.  |  
				
|  
					  Interface Config Change  |  
				   
					  ISIS was enabled or disabled on a port.  |  
				
|  
					  User Trigger  |  
				   
					  The user issued the clear isis spf-trigger command.  |  
				
|  
					  Recompute InterLeve Routes  |  
				   
					  The neighbor IS-type is changed either from L1 to L12 or L12 to L1  |  
				
|  
					  Exited Overload State  |  
				   
					  IS-IS exited from an overload condition.  |  
				
The following is sample output for the show isis spf-log command.
device# show isis spf-log ISIS Level-1 SPF Log When Duration Nodes Count Last-Trigger-LSP Trigger 10h34m13s 0ms 1 10 R1.00-00 Interface State Change 10h34m38s 0ms 1 2 R1.00-00 Interface Config Change 10h34m43s 0ms 1 18 R1.00-00 Interface Config Change 10h34m48s 0ms 1 5 R1.00-00 Interface State Change ISIS Level-2 SPF Log When Duration Nodes Count Last-Trigger-LSP Trigger 10h34m13s 0ms 1 10 R1.00-00 Interface State Change 10h34m38s 0ms 1 2 R1.00-00 Interface Config Change 10h34m43s 0ms 1 18 R1.00-00 Interface Config Change 10h34m48s 0ms 1 5 R1.00-00 Interface State Change
The following is sample output for the show isis spf-log command when the detail keyword is used.
device# show isis spf-log detail
ISIS Level-1 SPF Log
 When      Duration Nodes Count Last-Trigger-LSP         Trigger
  12h18m45s 0ms      1     10    R1.00-00             Interface State Change    
  Ipv4 Route updates: 0 Ipv6 Route updates: 0
        First Trigger: 12h18m50s Ve 305 State Changed to Up
  12h19m10s 0ms      1     2     R1.00-00             Interface Config Change   
  Ipv4 Route updates: 0 Ipv6 Route updates: 0
        First Trigger: 12h19m15s Ve 310 State Changed to Down
  12h19m15s 0ms      1     18    R1.00-00             Interface Config Change   
  Ipv4 Route updates: 0 Ipv6 Route updates: 0
        First Trigger: 12h19m18s Ve 301 State Changed to Down
  12h19m20s 0ms      1     5     R1.00-00             Interface State Change    
  Ipv4 Route updates: 0 Ipv6 Route updates: 0
        First Trigger: 12h19m25s LSP R1.00-00 Area Address TLV Changed
ISIS Level-2 SPF Log
 When      Duration Nodes Count Last-Trigger-LSP         Trigger
  12h18m45s 0ms      1     10    R1.00-00             Interface State Change    
  Ipv4 Route updates: 0 Ipv6 Route updates: 0
        First Trigger: 12h18m50s Ve 305 State Changed to Up
  12h19m10s 0ms      1     2     R1.00-00             Interface Config Change   
  Ipv4 Route updates: 0 Ipv6 Route updates: 0
        First Trigger: 12h19m15s Ve 310 State Changed to Down
  12h19m15s 0ms      1     18    R1.00-00             Interface Config Change   
  Ipv4 Route updates: 0 Ipv6 Route updates: 0
        First Trigger: 12h19m18s Ve 301 State Changed to Down
  12h19m20s 0ms      1     5     R1.00-00             Interface State Change  
…
 
	  
	  
		The following is sample output for the show isis spf-log command when the level-1 keyword is used.
device# show isis spf-log level-1 ISIS Level-1 SPF Log When Duration Nodes Count Last-Trigger-LSP Trigger 12h19m40s 0ms 1 10 R1.00-00 Interface State Change 12h20m5s 0ms 1 2 R1.00-00 Interface Config Change 12h20m10s 0ms 1 18 R1.00-00 Interface Config Change 12h20m15s 0ms 1 5 R1.00-00 Interface State Change