Monitoring Interfaces and Transceivers Using ethtool
The ethtool command enables you to query or control the network driver and hardware settings. It takes the device name (like swp1) as an argument. When the device name is the only argument to ethtool, it prints the network device settings. See man ethtool(8) for details.
The l1-show command is the preferred tool for monitoring Ethernet data. See the Troubleshoot Layer 1 guide for details.
Monitor Interface Status Using ethtool
To check the status of an interface with ethtool:
cumulus@switch:~$ ethtool swp1
Settings for swp1:
Supported ports: [ FIBRE ]
Supported link modes: 1000baseT/Full
10000baseT/Full
Supported pause frame use: No
Supports auto-negotiation: No
Advertised link modes: 1000baseT/Full
Advertised pause frame use: No
Advertised auto-negotiation: No
Speed: 10000Mb/s
Duplex: Full
Port: FIBRE
PHYAD: 0
Transceiver: external
Auto-negotiation: off
Current message level: 0x00000000 (0)
Link detected: yes
The switch hardware contains the active port settings. The output of ethtool swpXX shows the port settings in the kernel. The switchd process keeps the hardware and kernel in sync for the important port settings (speed, auto-negotiation, and link detected). However, some fields in ethtool, such as Supported Link Modes and Advertised Link Modes, do not update based on the actual module in the port and therefore can show incorrect or misleading results.
To query interface statistics:
cumulus@switch:~$ sudo ethtool -S swp1
NIC statistics:
HwIfInOctets: 1435339
HwIfInUcastPkts: 11795
HwIfInBcastPkts: 3
HwIfInMcastPkts: 4578
HwIfOutOctets: 14866246
HwIfOutUcastPkts: 11791
HwIfOutMcastPkts: 136493
HwIfOutBcastPkts: 0
HwIfInDiscards: 0
HwIfInL3Drops: 0
HwIfInBufferDrops: 0
HwIfInAclDrops: 28
HwIfInDot3LengthErrors: 0
HwIfInErrors: 0
SoftInErrors: 0
SoftInDrops: 0
SoftInFrameErrors: 0
HwIfOutDiscards: 0
HwIfOutErrors: 0
HwIfOutQDrops: 0
HwIfOutNonQDrops: 0
SoftOutErrors: 0
SoftOutDrops: 0
SoftOutTxFifoFull: 0
HwIfOutQLen: 0
View and Clear Interface Counters
Interface counters provide information about an interface. You can view this information when you run cl-netstat, ifconfig, or cat /proc/net/dev. You can also run cl-netstat to save or clear this information:
cumulus@switch:~$ sudo cl-netstat
Kernel Interface table
Iface MTU Met RX_OK RX_ERR RX_DRP RX_OVR TX_OK TX_ERR TX_DRP TX_OVR Flg
---------------------------------------------------------------------------------------------
eth0 1500 0 611 0 0 0 487 0 0 0 BMRU
lo 16436 0 0 0 0 0 0 0 0 0 LRU
swp1 1500 0 0 0 0 0 0 0 0 0 BMU
cumulus@switch:~$ sudo cl-netstat -c
Cleared counters
| Option |
Description |
|---|---|
-c |
Copies and clears statistics but does not clear counters in the kernel or hardware. Note: The -c argument applies per user ID. You can override it with the -t argument to save statistics to a different directory. |
-d |
Deletes saved statistics, either the uid or the specified tag. Note: The -d argument applies per user ID. You can override it with the -t argument to save statistics to a different directory. |
-D |
Deletes all saved statistics. |
-l |
Lists saved tags. |
-r |
Displays raw statistics (unmodified output of cl-netstat). |
-t <tag name> |
Saves statistics with <tag name>. |
-v |
Prints cl-netstat version and exits. |
On Mellanox switches, Cumulus Linux updates physical counters to the kernel every two seconds and virtual interfaces (such as VLAN interfaces) every ten seconds. You cannot change these values. Because the update process takes a lower priority than other switchd processes, the interval might be longer when the system is under a heavy load.
Monitor Switch Port SFP/QSFP Hardware Information Using ethtool
To see hardware capabilities and measurement information on the SFP or QSFP module in a particular port, use the ethtool -m command. If the SFP/QSFP supports Digital Optical Monitoring (the Optical diagnostics support field is Yes in the output below), the optical power levels and thresholds also show below the standard hardware details.
In the sample output below, you can see that this module is a 1000BASE-SX short-range optical module, manufactured by JDSU, part number PLRXPL-VI-S24-22. The second half of the output displays the current readings of the Tx power levels (Laser output power) and Rx power (Receiver signal average optical power), temperature, voltage and alarm threshold settings.
cumulus@switch$ sudo ethtool -m swp3
Identifier : 0x03 (SFP)
Extended identifier : 0x04 (GBIC/SFP defined by 2-wire interface ID)
Connector : 0x07 (LC)
Transceiver codes : 0x00 0x00 0x00 0x01 0x20 0x40 0x0c 0x05
Transceiver type : Ethernet: 1000BASE-SX
Transceiver type : FC: intermediate distance (I)
Transceiver type : FC: Shortwave laser w/o OFC (SN)
Transceiver type : FC: Multimode, 62.5um (M6)
Transceiver type : FC: Multimode, 50um (M5)
Transceiver type : FC: 200 MBytes/sec
Transceiver type : FC: 100 MBytes/sec
Encoding : 0x01 (8B/10B)
BR, Nominal : 2100MBd
Rate identifier : 0x00 (unspecified)
Length (SMF,km) : 0km
Length (SMF) : 0m
Length (50um) : 300m
Length (62.5um) : 150m
Length (Copper) : 0m
Length (OM3) : 0m
Laser wavelength : 850nm
Vendor name : JDSU
Vendor OUI : 00:01:9c
Vendor PN : PLRXPL-VI-S24-22
Vendor rev : 1
Optical diagnostics support : Yes
Laser bias current : 21.348 mA
Laser output power : 0.3186 mW / -4.97 dBm
Receiver signal average optical power : 0.3195 mW / -4.96 dBm
Module temperature : 41.70 degrees C / 107.05 degrees F
Module voltage : 3.2947 V
Alarm/warning flags implemented : Yes
Laser bias current high alarm : Off
Laser bias current low alarm : Off
Laser bias current high warning : Off
Laser bias current low warning : Off
Laser output power high alarm : Off
Laser output power low alarm : Off
Laser output power high warning : Off
Laser output power low warning : Off
Module temperature high alarm : Off
Module temperature low alarm : Off
Module temperature high warning : Off
Module temperature low warning : Off
Module voltage high alarm : Off
Module voltage low alarm : Off
Module voltage high warning : Off
Module voltage low warning : Off
Laser rx power high alarm : Off
Laser rx power low alarm : Off
Laser rx power high warning : Off
Laser rx power low warning : Off
Laser bias current high alarm threshold : 10.000 mA
Laser bias current low alarm threshold : 1.000 mA
Laser bias current high warning threshold : 9.000 mA
Laser bias current low warning threshold : 2.000 mA
Laser output power high alarm threshold : 0.8000 mW / -0.97 dBm
Laser output power low alarm threshold : 0.1000 mW / -10.00 dBm
Laser output power high warning threshold : 0.6000 mW / -2.22 dBm
Laser output power low warning threshold : 0.2000 mW / -6.99 dBm
Module temperature high alarm threshold : 90.00 degrees C / 194.00 degrees F
Module temperature low alarm threshold : -40.00 degrees C / -40.00 degrees F
Module temperature high warning threshold : 85.00 degrees C / 185.00 degrees F
Module temperature low warning threshold : -40.00 degrees C / -40.00 degrees F
Module voltage high alarm threshold : 4.0000 V
Module voltage low alarm threshold : 0.0000 V
Module voltage high warning threshold : 3.6450 V
Module voltage low warning threshold : 2.9550 V
Laser rx power high alarm threshold : 1.6000 mW / 2.04 dBm
Laser rx power low alarm threshold : 0.0100 mW / -20.00 dBm
Laser rx power high warning threshold : 1.0000 mW / 0.00 dBm
Laser rx power low warning threshold : 0.0200 mW / -16.99 dBm