Interface statistics

Interface statistics

The interface statistics page lists all network ports that are utilized by the *Network Multimeter*.

The `Interface status` column contains generic information about each port. The `Interface ID` is a unique number enumerated for all network ports. The `Link pair` number covers two ports linked to each other in the "bridge mode". That is, traffic received from one port of the same link pair will be sent to the corresponding port of the same link pair, and vice verse. In "sink mode", the link pair number is irrelevant as no traffic is forwarded.

The `Speed setting` offers a possibility to change the speed of the port. A selection of all possible settings is presented. The default selection is `auto` for the highest possible speed. The `Speed` indicates whether a network cable is connected and which link speed has been negotiated.

The `Duplex` status shows whether the link is operated in full-duplex or half-duplex mode.

In case the *Allegro Network Multimeter* operates in bridge mode and two mutual interfaces do not have the samke link speed and duplex, a warning will be shown below the `Duplex` status for both interfaces.

The `Current receive/transmit utilization` summarizes the traffic received and sent by the network port. The value is calculated by the number of bytes received and sent in relation to full-duplex link speed.

A `PCAP` buttons allows capturing all traffic for that network port.

Next to the `Interface status` there are three graphs for the number of processed packets, the number of processed bytes, and possible error counters. Both packets and bytes statistics show past values in the graph and the current total values and the current rate during the last second, separately for receiving (yellow down arrow) and sending side (blue up arrow).

The error values list all possible packet processing errors. Depending on the network interface card´s capabilities, slightly different counters are shown.

`RX errors` apply to received packets. Following errors are counted:

- `Malformed packets`: The packet was corrupt. This is a general receive

 error counter and more detailed counters will be reported below.

- `Hardware miss`: The packet couldn't be received by the network

 interface card.

- `Out of packet buffer`: There have been problems with allocating memory

 for the packet.

- `Undersized`: The packet was shorter than the minimum size of 64 Bytes

 and had a valid CRC.

- `Oversized`: The packet exceeded the defined MTU. - `Under or oversized`: The packet was either too small or it exceeded MTU. - `Bad CRC`: Frame check sequence of layer 2 was broken. - `Bad fragmentation`: The packet was was shorter than the minimum size of 64 Bytes

 and had a bad CRC.

- `Jabber`: The packet was longer than the MTU and had a bad CRC.

`TX errors` indicates errors when sending to the wire fails for some reason.

- `Unable to forward`: This is a generic error counter. - `Dropped due to missing capacity`: The packet could not be sent as the link

 capacity was too small.

`Not processed` packets were dropped due to overloaded software send queues.