Viewing Port Statistics
- 25 Jan 2024
- 12 Minutes to read
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Viewing Port Statistics
- Updated on 25 Jan 2024
- 12 Minutes to read
- Contributors
- Print
- DarkLight
- PDF
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You can view a summary and a detailed port statistics for each port. The port’s statistics are sampled once per second.
Note: Bandwidth utilization Statistics are provided for physical ports only (i.e. traffic and Management), not for Monitor ports.
To view a summary of statistics for all ports
Access the page Port ▶Statistics.
(Optional) Select the Clear icon to clear the statistics.
For more information on specific parameters, refer to the following table.
To view the detailed port statistics
Access the page Port ▶Statistics.
Select a port name by clicking it.
The < port name > Port Statistics page appears. Transmit and Receive statistics for the selected port are displayed.(Optional) Select the Poll Every n Seconds box and enter the number of seconds between each time the data is automatically refreshed. You can also refresh the port statistics by clicking the Refresh button.
Tip: Click the Clear button to reset all counters to 0.
For more information on specific parameters, refer to the following table.
Port Statistics (Port ▶Statistics)
Summary Page
| Parameter | Description |
|---|---|
| Port Name | The port for which statistics are displayed. |
| Txm Packets | The total number of frames/packets (both good and bad) transmitted by the port. Bad frames include normal collisions, late collisions and FIFO underflows. |
| Txm Errors | Number of transmission errors. |
| Rcv Packets | The total number of frames/packets (both good and bad) received by the port. Bad frames include short frames (less than 64 bytes), long frames (greater than the port's configured MTU), frames with bad CRC, frames with PHY errors and frames with receive FIFO errors. |
| Rcv Errors | Number of errors received. |
Transmit Statistics
| Parameter | Description |
|---|---|
| Bytes Good | The total number of bytes transmitted by the port in good frames. The number of bytes includes the four CRC bytes but does not include the preamble or SFD bytes. A good frame is one that has been transmitted successfully (not aborted) with a valid CRC. It is assumed that all transmitted frames are properly sized: from 64 bytes (after any padding) up to the maximum size. |
| Bytes Total | The total number of frames/packets (both good and bad) transmitted by the port. Bad frames include normal collisions, late collisions and FIFO underflows. |
| Unicast Packets | The count of the good (not dropped and having a valid CRC) unicast frames transmitted by this port. Unicast frames are identified by having a 0 in the least significant bit of the first byte of the destination address (the first bit transmitted is a 0). |
| Multicast Packets | The count of the good (not dropped and having a valid CRC) multicast frames transmitted by this port. Multicast frames are identified by having a 1 in the least significant bit of the first byte of the destination address (i.e. the first bit transmitted is a 1). Broadcast frames are not included in this count. |
| Broadcast Packets | The count of the good (not dropped and having a valid CRC) broadcast frames transmitted by this port. Broadcast frames are identified by a destination address consisting of all 1s. |
| Pause Frames | The count of the good (not dropped and having a valid CRC) flow control pause frames transmitted by this port. Flow control pause frames are identified by a type of 88-08 and an OpCode field of 00-01. |
| Tagged Frames | The count of the good (not dropped and having a valid CRC) VLAN frames transmitted by this port. VLAN frames are identified by a type field equal to 8100h, 88A8h or 9100h, set in the outer VLAN tag. |
| CRC Errors | The count of the transmitted frames with an invalid non-appended CRC field. This count does not include frames with an invalid CRC resulting from a FIFO underflow. |
| Deferred | The number of frames that were deferred on the first transmit attempt due to the medium being busy. Frames with subsequent deferrals (for example, after a collision back off) are not counted. Whether or not the frame is eventually transmitted successfully is irrelevant to this counter. Frames dropped due to excess deferral during the initial transmit attempt are not counted. |
| Excessive Deferrals | The number of frames dropped by this port due to excessive deferral. The deferral time starts at the beginning of each transmission attempt and ends when the transmission starts (regardless of collisions). The deferral is excessive if more than 3036 byte times have passed without the transmission starting. |
| Single Collisions | The number of times a frame was successfully transmitted from this port after experiencing a single collision. This count does not include erroneous (dropped) frames. |
| Multiple Collisions | The number of times a frame was successfully transmitted from this port after experiencing multiple collisions. This number does not include erroneous (dropped) frames or frames dropped due to excess collisions. |
| Excessive Collisions | The number of frames dropped by this port due to excess collisions (number of collisions equals MaxRetry+1) This number does not include frames dropped due to FIFO underflow or late collisions (even if the late collision is also an excessive collision). |
| Late Collisions | The number of frames dropped by this port due to late collisions. A late collision is an impact that occurs after the collision window delay (typically 512-bit times). The collision window time is measured from the rising edge of TX_EN to COL asserted at the MII interface. Note: This number does not include frames dropped due to FIFO underflow. Late collisions are not retried. |
| Normal Collisions | The total number of normal collisions that have occurred on this port during all transmission attempts. FIFO underflows, late collisions and collisions that occur while this port was not attempting to transmit are not counted. This number does not include collisions during half-duplex back pressure. |
| FIFO Errors | The number of packets dropped by this port due to an underflow in the transmit FIFO. When an underflow is detected, transmission is immediately aborted after sending a known invalid (inverted) CRC sequence. The FIFO underflow error takes precedence over all other errors if this counter is incremented. Consequently, none of the other frame type counters is incremented |
| Packets 64 | The total number of frames (good and bad) transmitted by this port that were exactly 64 bytes in length (excluding the preamble and SFD, but including the CRC). |
| Packets 65–127 Packets 128–255 Packets 256–511 Packets 512– 1023 Packets 1024–1518 Packets 1519–2047 Packets 2048–4095 Packets 4096–8191 Packets 8192 and up | The total number of frames (good or bad) transmitted by this port that were of the length indicated in the parameter column This frame length value excludes the preamble and SFD, but includes the CRC. Note: Frames with a length of 1024 and above are only available on certain types of units. |
| Large Packets | The total number of large frames transmitted by this port. You can define the size of large frames via the Large Packet Threshold parameter of the **Port ▶Configuration ▶[port name]**page. |
| L1 Bandwidth Utilization (%) | The bandwidth currently used for the transmission of outgoing traffic on the selected port, expressed as a percentage of the line rate. Notes: Bandwidth utilization statistics are provided with onesecond granularity for both Layer-1 and Layer-2; however, the value expressed as a percentage of the line rate is available for Layer-1 only. Statistics will be accurate to ±1% at data rates above 100 Mbps. |
| L1 Rate (Mbps) | The rate at which outgoing traffic is currently circulating at Layer-1 for the selected port, expressed in Mbps. |
| L2 Rate (Mbps) | The rate at which outgoing traffic is currently circulating at Layer-2 for the selected port, expressed in Mbps. |
Receive Statistics
| Parameter | Description |
|---|---|
| Bytes Good | The total number of bytes transmitted by the port in good frames. The number of bytes includes the four CRC bytes but does not include the preamble or SFD bytes. A good frame is one that has been transmitted successfully (not aborted) with a valid CRC. It is assumed that all transmitted frames are properly sized: from 64 bytes (after any padding) up to the maximum size. |
| Bytes Total | The total number of frames/packets (both good and bad) transmitted by the port. Bad frames include normal collisions, late collisions and FIFO underflows. |
| Short OK | The number of error-free frames shorter than 64 bytes that were received on this port. A frame is considered error-free if it has a valid CRC, no PHY errors and no FIFO errors. |
| Short Bad | The number of frames received on this port that were shorter than 64 bytes and have an invalid CRC. Frames with PHY or FIFO errors are not counted. |
| Long OK | The number of error-free frames received that are longer than the MTU configured on the port. A frame is considered error-free if it has a valid CRC, no PHY errors and no FIFO errors. |
| Long Bad | The number of frames received that are longer than the MTU configured on the port and have an invalid CRC. Frames with PHY or FIFO errors are not counted. |
| Unicast Packets | The number of the good unicast frames received by this port. A good unicast frame is a normally-sized frame (64 to MTU configured on the port) that is not dropped and has a good CRC. Unicast frames are identified by having a 0 in the least significant bit of the first byte of the destination address (i.e. the first bit received is a 0). |
| Multicast Packets | The number of good multicast frames received by this port. A good multicast frame is a normally-sized frame (64 to MTU configured on the port) that is not dropped and has a good CRC. Multicast frames are identified by having a 1 in the least significant bit of the first byte of the destination address (i.e. the first bit received is a 1). Broadcast frames are not included in this number. |
| Broadcast Packets | The number of good broadcast frames received by this port. A good broadcast frame is a normal-sized frame (64 to MTU configured on the port) that is not dropped and has a good CRC. Broadcast frames are identified by a destination address of all 1s. |
| Pause Frames | The number of good flow control pause frames received by this port (good CRC, no PHY or FIFO errors, normal size). Flow control pause frames are identified by a type of 88-08 and an OpCode field of 00- 01. |
| Tagged Frames | The number of good VLAN frames received by this port (good CRC, no PHY or FIFO errors, normally sized). |
| CRC Errors | The number of normally-sized frames (64 to MTU configured on the port) received by this port with a CRC error but not a dribbling nibble (frame length is an integral number of bytes). Frames with FIFO or PHY errors are not counted. |
| Align Errors | The number of normally-sized frames (64 to MTU configured on the port) received by this port with a CRC error and a dribbling nibble (frame length is not an integral number of bytes). Frames with PHY or FIFO errors are not counted. |
| Runt Frames | The number of received frames (or events) detected by this port without SFD detection but with carrier assertion. Frames with valid SFD but no data bytes are also counted as runts. After detecting a runt frame, the update of the RxRunts counter is suspended until the next valid frame is received. If multiple runt frames occur between valid frames, the RxRunts counter is incremented only once. |
| Length Errors | The number of good frames received by this port with an error in the length field. A length error occurs when the value in the length field is within the valid range for data length (46–1500 bytes) but does not match the actual data length of the frame. Field lengths less than 46 bytes (smaller than the minimum legal frame size of 64 bytes) are not checked, due to padding. |
| False CRS | The number of received frames (or events) detected by this port with a false carrier (SSD1 not followed by SSD2). After detecting a false carrier, updating the RxFalseCRS counter is suspended until the next valid frame is received. If multiple false carrier events occur between valid frames, the RxFalseCRS counter is incremented only once. |
| PHY Errors | The number of frames received by this port with RX_ER asserted during reception (while RX_DV is asserted). Frames with a FIFO error are not counted. |
| FIFO Errors | The number of received frames dropped or aborted due to receiving a FIFO overflow. The FIFO overflow error takes precedence over all other errors; if this counter is incremented, then none of the other frame counters is incremented. |
| Ignored | The number of received frames that have been ignored by this port. A frame is ignored if it violates the programmed preamble rules or if it violates the minimum data gap. The preamble rules include long preamble enforcement (greater than 23 nibbles) and pure preamble enforcement (only 55h bytes). The minimum data gap is the time between frame data transfers and is measured from immediately after the last CRC byte of the previous frame to the SFD field of the current frame. The normal data gap is 20 bytes long (12 bytes of IFG and 8 bytes of preamble/SFD). The enforcement limit is set to 10 bytes (half the normal gap length). |
| Bad OpCode | The number of good control frames received by this port (good CRC, no PHY or FIFO errors, normally sized) with an unknown OpCode. Unknown control frames are identified by a type field of 88–08 and an OpCode field not equal to 00–01. |
| Packets 64 | The total number of frames, good or bad, received by this port, that were exactly 64 bytes in length (excluding preamble and SFD but including CRC). |
| Packets 65–127 Packets 128–255 Packets 256–511 Packets 512– 1023 Packets 1024–1518 Packets 1519–2047 Packets 2048–4095 Packets 4096–8191 Packets 8192 and up | The total number of frames (good and bad) received by this port, that were 65–127 bytes (or the other length) in length inclusive (excluding the preamble and SFD, but including the CRC). Note: Frames with a length of 1024 and above are only available on certain types of units. |
| Large Packets | The total number of large frames transmitted by this port. The size of Large Packet Threshold is defined in the **Port ▶Configuration ▶[port name]**page. |
| L1 Bandwidth Utilization (%) | The bandwidth currently used for the transmission of outgoing traffic on the selected port, expressed as a percentage of the line rate. Notes: Bandwidth utilization statistics are provided with onesecond granularity for both Layer-1 and Layer-2; however, the value expressed as a percentage of the line rate is available for Layer-1 only. Statistics will be accurate to ±1% at data rates above 100 Mbps. |
| L1 Rate (Mbps) | The rate at which incoming traffic is currently circulating at Layer-1 for the selected port, expressed in Mbps. |
| L2 Rate (Mbps) | The rate at which incoming traffic is currently circulating at Layer-2 for the selected port. Expressed in Mbps. |
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