Displays IS-IS error statistics.
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".
| 
									 Output field  | 
								
									 Description  | 
							
|---|---|
| 
									 Area Mismatch  | 
								
									 The number of times the device interface was unable to create a Level-1 adjacency with a neighbor because the device interface and the neighbor did not have any areas in common.  | 
							
| 
									 Max Area Mismatch  | 
								
									 The number of times the device received a PDU whose value for maximum number of area addresses did not match the device‘s value for maximum number of area addresses.  | 
							
| 
									 System ID Length Mismatch  | 
								
									 The number of times the device received a PDU whose ID field was a different length than the ID field length configured on the device.  | 
							
| 
									 LSP Sequence Number Skipped  | 
								
									 The number of times the device received an LSP with a sequence number that was more than 1 higher than the sequence number of the previous LSP received from the same neighbor.  | 
							
| 
									 LSP Max Sequence Number Exceeded  | 
								
									 The number of times the device attempted to set an LSP sequence number to a value higher than the highest number in the CSNP sent by the Designated IS.  | 
							
| 
									 Level-1 Database Overload  | 
								
									 The number of times the Level-1 state on the device changed from Waiting to On or from On to Waiting. 
  | 
							
| 
									 Level-2 Database Overload  | 
								
									 The number of times the Level-2 state on the device changed from Waiting to On or from On to Waiting. 
  | 
							
| 
									 Our LSP Purged  | 
								
									 The number of times the device received an LSP that was originated by the device itself and had age zero (aged out).  | 
							
| 
									 PDU Drop Count  | 
								
									 
  | 
							
| 
									 CSNP Auth Failures  | 
								
									 The number of CSNP Authentication failures recorded for Level-1 and Level-2. This counter will only be displayed if it has a value greater than zero.  | 
							
| 
									 PSNP Auth Failures  | 
								
									 The number of PSNP Authentication failures recorded for Level-1 and Level-2. This counter appears only if it has a value greater than 0.  | 
							
| 
									 HELLO Auth Failures  | 
								
									 The number of HELLO Authentication failures recorded for Level-1 and Level-2. This counter will only be displayed if it has a value greater than zero.  | 
							
| 
									 Adjacency not found  | 
								
									 The number of PDUs dropped at both Level-1 and Level-2 because there is no valid adjacency on the interface where they were received. This counter will only be displayed if it has a value greater than zero.  | 
							
| 
									 Adjacency Level Mismatch  | 
								
									 The number of PDUs dropped at both Level-1 and Level-2 because the adjacency from which the PDU is received has a different level than the PDU level. This counter will only be displayed if it has a value greater than zero.  | 
							
| 
									 IS Level Mismatch  | 
								
									 The number of PDUs dropped at both Level-1 and Level-2 because the IS-IS router level mismatches with the PDU level received. This counter will only be displayed if it has a value greater than zero.  | 
							
| 
									 Length Too Short  | 
								
									 The number of PDUs dropped at both Level-1 and Level-2 because the received PDU length is less than the standard PDU header length. This counter will only be displayed if it has a value greater than zero.  | 
							
| 
									 Length Too Long  | 
								
									 The number of PDUs dropped at both Level-1 and Level-2 because the received PDU length is greater than the MTU of the link. This counter will only be displayed if it has a value greater than zero.  | 
							
| 
									 Max Area Check Failure  | 
								
									 The number of PDUs dropped at both Level-1 and Level-2 because the received PDU has a maximum area count different than what is configured on this IS-IS router. This counter will only be displayed if it has a value greater than zero.  | 
							
| 
									 Zero Checksum  | 
								
									 The number of PDUs dropped at both Level-1 and Level-2 because the received PDU has a zero checksum. This counter will only be displayed if it has a value greater than zero.  | 
							
| 
									 Checksum Mismatch  | 
								
									 The number of PDUs dropped at both Level-1 and Level-2 because the received PDU has a checksum different than the computed checksum on the received PDU. This counter will only be displayed if it has a value greater than zero.  | 
							
| 
									 Invalid Length  | 
								
									 The number of PDUs dropped at both Level-1 and Level-2 because the received PDU has a different length than what is advertised in the PDU header. This counter will only be displayed if it has a value greater than zero.  | 
							
The following example displays sample output from the show isis counts command.
device# show isis counts Area Mismatch: 0 Max Area Mismatch: 0 System ID Length Mismatch: 0 LSP Sequence Number Skipped: 0 LSP Max Sequence Number Exceeded: 0 Level-1 Database Overload: 0 Level-2 Database Overload: 0 Our LSP Purged: 0