This counts the total number of received packets that carried IP options in their header. Because IP options are rare in typical modern traffic and sometimes associated with network diagnostic tools, like source routing or record-route probes, or occasionally malformed or crafted packets, a rising count here on a link that should not normally see IP-options traffic could be worth investigating for either misbehaving equipment or unusual, probing traffic. An unexpected rise in this counter on a link normally carrying only plain VoIP and file-transfer traffic might prompt an admin to capture and inspect that unusual options-carrying traffic to determine its source and purpose.