When one VLANIF interface is configured on the S3300/S5300EI, the switch delivers an ACL to match ARP packets in the corresponding VLAN so that the matched packets are sent to the control plane. If more than eight VLANIF interfaces are configured on the S3300 or more than 32 VLANIF interfaces are configured on the S5300EI, the switch delivers only one ACL to match all ARP packets in the corresponding VLAN so that all these packets are sent to the control plane for processing. This ACL also matches Layer 2 ARP packets on other interfaces in the same VLAN. If too many Layer 2 ARP packets are forwarded, the control plane is overloaded and the CPU usage becomes high.