The full text of the behavior change line:
Performance on the C3000 and C3010 systems is currently degraded when compared to the 6.11.x performance. In some cases this is up to 20% lower performance. Customers are advised to compare their existing system performance against the Scaling and Ordering Guide information published with 6.12 updates.
The performance degradation is due to a kernel level fix and is not something that will be resolved directly which is why this is noted under "Behavior Changes" rather than "Known Issues". Check the latest version of the Scaling and Ordering Guide to determine if the change would have any impact on your particular environment (looking specifically at TACACS+ numbers as that's where the impact was originally noted).
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Carson Hulcher, ACEX#110
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