# Hardware Counters

This page displays hardware counters to help monitor the NetScreen device. The hardware counters provide information on hardware performance.

### Viewing the Hardware Counters

- From the Interface drop-down list, select the interface for which you want to view the counters.

- Click Refresh whenever you want to update the hardware counters with the most recent statistics.

### Interpreting the Hardware Counters

The hardware counters provide the following information:

drop vlan: Indicates the number of dropped packets because of missing VLAN tags, an undefined subinterface, or because VLAN trunking was not enabled when the NetScreen device was in Transparent mode.

early frame: Indicates counters used in an ethernet driver buffer descriptor management.

in align err: Indicates the number of incoming packets with an alignment error in the bit stream.

in bytes: Indicates the number of bytes received.

in coll err: Indicates the number of incoming collision packets.

in crc err: Indicates the number of incoming packets with a cyclic redundancy check (CRC) error.

in dma err: Indicates the number of incoming packets with a dma error.

in misc err: Indicates the number of incoming packets with a miscellaneous error.

in no buffer: Indicates the number of unreceivable packets because of unavailable buffers.

in overrun: Indicates the number of transmitted overrun packets.

in packets: Indicates the number of packets received.

in short frame: Indicates the number of incoming packets with an in-short frame error.

late frame: Indicates counters used in an ethernet driver buffer descriptor management.

out bs pak: Indicates the number of packets held in back store while searching for an unknown MAC address.

out bytes: Indicates the number of bytes sent.

out coll err: Indicates the number of outgoing collision packets.

out cs lost: Indicates the number of dropped outgoing packets because of a lance transmission error.

out defer: Indicates the number of deferred outgoing packets.

out discard: Indicates the number of discarded outgoing packets.

out heartbeat: Indicates the number of outgoing heartbeat packets.

out misc err: Indicates the number of outgoing packets with a miscellaneous error.

out no buffer: Indicates the number of unsent packets because of unavailable buffers.

out packets: Indicates the number of packets sent.

out underrun: Indicates the number of transmitted underrun packets.

re xmt limit: Indicates the number of dropped packets when the retransmission limit was exceeded.

Note: You can also view a screen counters report that provides information on general firewall behavior, and a flow counters report that provides information on the number of packets inspected at the flow level.