This counter tracks packets CEF couldn't handle on the primary fast path and instead punted to the next-fastest available switching mechanism. A rising punt count signals that some traffic is bypassing CEF's optimal hardware or software fast path, commonly due to features like fragmentation, TTL expiry, or unsupported encapsulation that CEF can't process inline, which increases per-packet CPU cost. An admin seeing this counter spike after enabling a new feature like NAT or a complex ACL on an interface would suspect that feature isn't fully supported in the CEF fast path and is forcing packets to a slower vector.