Core Issue
On routers running Enhanced Interior Gateway Routing Protocol (EIGRP), an error message indicating that the neighbor is down due to K-value mismatch might appear for these reasons:
- Different settings for metric calculation on the EIGRP neighbors. By default, EIGRP uses bandwidth and delay to compute routing metrics. However, additional parameters such as load and reliability can be used while computing the metric by modifying the value of the corresponding multipliers (k-value). Two routers with different K-values figured on them do not become neighbors and generate the k-value mismatch error.
- An EIGRP router running Cisco IOS version 12.3 signals an immediate disconnect to another EIGRP neighbor by changing the k-values. If the receiving router uses an older version and does not recognize this as a graceful shutdown, it generates this k-value mismatch error.
Resolution
If the k values have been changed by issuing the metric weights command, ensure that the change is made across all routers through the domain and that the configured k-values are identical. For more information, refer to EIGPR Metrics section of Enhanced Interior Gateway Routing Protocol.
If the error message is due to Cisco bug ID CSCdr96531, the message can be safely ignored. Cisco bug ID CSCec06478 is a cosmetic bug, and does not cause any problem to the EIGRP functionality.
EIGRP Errors, Warnings, and Log Messages
Error message not in list