This per-interface object shows, and lets you set, whether CEF switching is enabled, running in distributed mode, or disabled for packets arriving on that interface. Since this only governs the received-packet path on the interface, an admin troubleshooting asymmetric performance would check this value to confirm CEF hasn't quietly dropped to cefDisabled(3) on one interface while staying enabled elsewhere, forcing incoming traffic on that link into slow-path processing. On a distributed platform like a 7600 with line cards, you'd expect distCefEnabled(2) on every interface; finding cefEnabled(1) on one port instead would flag that its line card isn't participating in distributed CEF.