display isis spf-log

Function

The display isis spf-log command displays the SPF calculation log of IS-IS.

Format

display isis process-id spf-log spf [ ipv6 | [ topology topology-name ] | [ level-1 | level-2 ] ] ^*

display isis spf-log [ process-id | vpn-instance vpn-instance-name ] spf [ ipv6 | [ level-1 | level-2 ] ] ^*

display isis process-id spf-log frr [ ipv6 | [ level-1 | level-2 ] ] ^*

display isis spf-log [ process-id | vpn-instance vpn-instance-name ] frr [ ipv6 | [ level-1 | level-2 ] ] ^*

display isis process-id spf-log prc [ ipv6 | [ topology topology-name ] ] ^*

display isis spf-log [ process-id | vpn-instance vpn-instance-name ] prc [ ipv6 ]

display isis [ process-id ] spf-log [ spf | prc | frr | ipv6 ]

Parameters

Parameter	Description	Value
process-id	Specifies an IS-IS process ID.	The value is an integer ranging from 1 to 4294967295.
spf	Indicates the SPF calculation log.	-
ipv6	Indicates the SPF calculation log in the IPv6 topology.	-
topology topology-name	Specifies the name of a topology instance.	The value is a string of 1 to 31 case-sensitive characters without spaces. The value must start with a letter (a to z or A to Z, case sensitive) and can contain numbers, hyphens (-), or underlines (_). When double quotation marks are used around the string, spaces are allowed in the string.
level-1	Indicates the SPF calculation log in a Level-1 area.	-
level-2	Indicates the SPF calculation log in a Level-2 area.	-
vpn-instance vpn-instance-name	Specifies the name of a VPN instance.	The value is a string of 1 to 31 case-sensitive characters, spaces not supported. In addition, the VPN instance name must not be _public_. When double quotation marks are used around the string, spaces are allowed in the string.
frr	Indicates the FRR calculation log.	-
prc	Indicates the PRC calculation log.	-

Views

All views

Default Level

1: Monitoring level

Task Name and Operations

Task Name	Operations
isis	read

Usage Guidelines

Usage Scenario

When an error occurs in the IS-IS SPF calculation, run the display isis spf-log command to diagnose the fault. The command can be used to view the SPF calculation log of IS-IS, such as the start time, duration, number of nodes, and events that trigger the SPF calculation. You can check which event causes the error of the SPF calculation by the start time.

Check the StartTime field first. If the SPF calculation is performed repeatedly at short intervals, flapping may have occurred. Then check the Last Trigger LSP and Trigger Event fields for further analysis.

Example

The actual command output varies according to the device. The command output here is only an example.

# Display the SPF calculation log of IS-IS.

<HUAWEI> display isis spf-log
                        SPF Log information for ISIS(1)
                        -------------------------------
                            ISIS(1) Level-1 SPF Log
                            -----------------------
 StartTime  Duration  Nodes  Count  Last Trigger LSP      Trigger Event
--------------------------------------------------------------------------------
 15:11:28   0         0      1      NULL                  ISPF_ADJ_STATE_CHG
 15:11:6    0         2      2      NULL                  ISPF_CIRC_DR_CHANGE
 15:9:30    0         0      4      1111.1111.1111.00-00  TUNNEL_ADJ_UP
 15:9:20    0         2      3      NULL                  ISPF_LINK_ADD
 15:3:36    0         0      1      NULL                  ISPF_ADJ_STATE_CHG
 15:3:15    0         2      2      NULL                  ISPF_CIRC_DR_CHANGE
 15:2:30    0         2      3      NULL                  ISPF_LINK_ADD
 15:1:40    0         0      1      NULL                  ISPF_ADJ_STATE_CHG
 15:1:30    0         2      2      NULL                  ISPF_CIRC_DR_CHANGE
 14:2:39    0         1      5      1111.1111.1111.00-00  ISPF_LINK_DEL
 13:5:49    0         1      2      NULL                  ISPF_LINK_ADD
 13:5:39    0         2      5      NULL                  ISPF_ADJ_PROT_CHG
 13:5:17    0         2      2      NULL                  ISPF_CIRC_DR_CHANGE
 11:12:19   0         0      3      NULL                  ISPF_2WAY_CHECK
 10:27:32   0         0      3      NULL                  ISPF_2WAY_CHECK
 9:54:12    0         2      8      NULL                  ISPF_LINK_ADD
 9:54:2     0         2      2      NULL                  ISPF_CIRC_DR_CHANGE
 9:38:33    0         0      4      1111.1111.1111.00-00  TUNNEL_ADJ_UP
 9:38:12    0         0      1      NULL                  ISPF_ADJ_NEXTHOP_CHG
 9:38:2     0         2      3      NULL                  ADJDOWN

**Table 1** Description of the **display isis spf-log** command output
Item	Description
StartTime	Start time for SPF calculation.
Duration	Time taken for SPF calculation, the value rounds down the actual duration, in milliseconds. In most cases, the value is less than 1 ms. Therefore, it is displayed as 0.
Nodes	Number of nodes calculated by SPF.
Count	Number of events triggering the SPF calculation.
Last Trigger LSP	LSP that triggers the last SPF calculation.
Trigger Event	Event that triggers the last SPF calculation.