What: /sys/class/net//name_assign_type Date: July 2014 KernelVersion: 3.17 Contact: netdev@vger.kernel.org Description: Indicates the name assignment type. Possible values are: == ========================================================== 1 enumerated by the kernel, possibly in an unpredictable way 2 predictably named by the kernel 3 named by userspace 4 renamed == ========================================================== What: /sys/class/net//addr_assign_type Date: July 2010 KernelVersion: 3.2 Contact: netdev@vger.kernel.org Description: Indicates the address assignment type. Possible values are: == ============================= 0 permanent address 1 randomly generated 2 stolen from another device 3 set using dev_set_mac_address == ============================= What: /sys/class/net//addr_len Date: April 2005 KernelVersion: 2.6.12 Contact: netdev@vger.kernel.org Description: Indicates the hardware address size in bytes. Values vary based on the lower-level protocol used by the interface (Ethernet, FDDI, ATM, IEEE 802.15.4...). See include/uapi/linux/if_*.h for actual values. What: /sys/class/net//address Date: April 2005 KernelVersion: 2.6.12 Contact: netdev@vger.kernel.org Description: Hardware address currently assigned to this interface. Format is a string, e.g: 00:11:22:33:44:55 for an Ethernet MAC address. What: /sys/class/net//bridge/group_fwd_mask Date: January 2012 KernelVersion: 3.2 Contact: netdev@vger.kernel.org Description: Bitmask to allow forwarding of link local frames with address 01-80-C2-00-00-0X on a bridge device. Only values that set bits not matching BR_GROUPFWD_RESTRICTED in net/bridge/br_private.h allowed. Default value 0 does not forward any link local frames. Restricted bits: == ======================================================== 0 01-80-C2-00-00-00 Bridge Group Address used for STP 1 01-80-C2-00-00-01 (MAC Control) 802.3 used for MAC PAUSE 2 01-80-C2-00-00-02 (Link Aggregation) 802.3ad == ======================================================== Any values not setting these bits can be used. Take special care when forwarding control frames e.g. 802.1X-PAE or LLDP. What: /sys/class/net//broadcast Date: April 2005 KernelVersion: 2.6.12 Contact: netdev@vger.kernel.org Description: Hardware broadcast address for this interface. Format is a string, e.g: ff:ff:ff:ff:ff:ff for an Ethernet broadcast MAC address. What: /sys/class/net//carrier Date: April 2005 KernelVersion: 2.6.12 Contact: netdev@vger.kernel.org Description: Indicates the current physical link state of the interface. Possible values are: == ===================== 0 physical link is down 1 physical link is up == ===================== Note: some special devices, e.g: bonding and team drivers will allow this attribute to be written to force a link state for operating correctly and designating another fallback interface. What: /sys/class/net//dev_id Date: April 2008 KernelVersion: 2.6.26 Contact: netdev@vger.kernel.org Description: Indicates the device unique identifier. Format is an hexadecimal value. This is used to disambiguate interfaces which might be stacked (e.g: VLAN interfaces) but still have the same MAC address as their parent device. What: /sys/class/net//dev_port Date: February 2014 KernelVersion: 3.15 Contact: netdev@vger.kernel.org Description: Indicates the port number of this network device, formatted as a decimal value. Some NICs have multiple independent ports on the same PCI bus, device and function. This attribute allows userspace to distinguish the respective interfaces. Note: some device drivers started to use 'dev_id' for this purpose since long before 3.15 and have not adopted the new attribute ever since. To query the port number, some tools look exclusively at 'dev_port', while others only consult 'dev_id'. If a network device has multiple client adapter ports as described in the previous paragraph and does not set this attribute to its port number, it's a kernel bug. What: /sys/class/net//dormant Date: March 2006 KernelVersion: 2.6.17 Contact: netdev@vger.kernel.org Description: Indicates whether the interface is in dormant state. Possible values are: 0: interface is not dormant 1: interface is dormant This attribute can be used by supplicant software to signal that the device is not usable unless some supplicant-based authentication is performed (e.g: 802.1x). 'link_mode' attribute will also reflect the dormant state. What: /sys/class/net//testing Date: April 2002 KernelVersion: 5.8 Contact: netdev@vger.kernel.org Description: Indicates whether the interface is under test. Possible values are: == ============================= 0 interface is not being tested 1 interface is being tested == ============================= When an interface is under test, it cannot be expected to pass packets as normal. What: /sys/class/net//duplex Date: October 2009 KernelVersion: 2.6.33 Contact: netdev@vger.kernel.org Description: Indicates the interface latest or current duplex value. Possible values are: ==== =========== half half duplex full full duplex ==== =========== Note: This attribute is only valid for interfaces that implement the ethtool get_link_ksettings method (mostly Ethernet). What: /sys/class/net//flags Date: April 2005 KernelVersion: 2.6.12 Contact: netdev@vger.kernel.org Description: Indicates the interface flags as a bitmask in hexadecimal. See include/uapi/linux/if.h for a list of all possible values and the flags semantics. What: /sys/class/net//ifalias Date: September 2008 KernelVersion: 2.6.28 Contact: netdev@vger.kernel.org Description: Indicates/stores an interface alias name as a string. This can be used for system management purposes. What: /sys/class/net//ifindex Date: April 2005 KernelVersion: 2.6.12 Contact: netdev@vger.kernel.org Description: Indicates the system-wide interface unique index identifier as a decimal number. This attribute is used for mapping an interface identifier to an interface name. It is used throughout the networking stack for specifying the interface specific requests/events. What: /sys/class/net//iflink Date: April 2005 KernelVersion: 2.6.12 Contact: netdev@vger.kernel.org Description: Indicates the system-wide interface unique index identifier a the interface is linked to. Format is decimal. This attribute is used to resolve interfaces chaining, linking and stacking. Physical interfaces have the same 'ifindex' and 'iflink' values. What: /sys/class/net//link_mode Date: March 2006 KernelVersion: 2.6.17 Contact: netdev@vger.kernel.org Description: Indicates the interface link mode, as a decimal number. This attribute should be used in conjunction with 'dormant' attribute to determine the interface usability. Possible values: == ================= 0 default link mode 1 dormant link mode == ================= What: /sys/class/net//mtu Date: April 2005 KernelVersion: 2.6.12 Contact: netdev@vger.kernel.org Description: Indicates the interface currently configured MTU value, in bytes, and in decimal format. Specific values depends on the lower-level interface protocol used. Ethernet devices will show a 'mtu' attribute value of 1500 unless changed. What: /sys/class/net//netdev_group Date: January 2011 KernelVersion: 2.6.39 Contact: netdev@vger.kernel.org Description: Indicates the interface network device group, as a decimal integer. Default value is 0 which corresponds to the initial network devices group. The group can be changed to affect routing decisions (see: net/ipv4/fib_rules and net/ipv6/fib6_rules.c). What: /sys/class/net//operstate Date: March 2006 KernelVersion: 2.6.17 Contact: netdev@vger.kernel.org Description: Indicates the interface RFC2863 operational state as a string. Possible values are: "unknown", "notpresent", "down", "lowerlayerdown", "testing", "dormant", "up". What: /sys/class/net//phys_port_id Date: July 2013 KernelVersion: 3.12 Contact: netdev@vger.kernel.org Description: Indicates the interface unique physical port identifier within the NIC, as a string. What: /sys/class/net//phys_port_name Date: March 2015 KernelVersion: 4.0 Contact: netdev@vger.kernel.org Description: Indicates the interface physical port name within the NIC, as a string. What: /sys/class/net//speed Date: October 2009 KernelVersion: 2.6.33 Contact: netdev@vger.kernel.org Description: Indicates the interface latest or current speed value. Value is an integer representing the link speed in Mbits/sec. Note: this attribute is only valid for interfaces that implement the ethtool get_link_ksettings method (mostly Ethernet). What: /sys/class/net//tx_queue_len Date: April 2005 KernelVersion: 2.6.12 Contact: netdev@vger.kernel.org Description: Indicates the interface transmit queue len in number of packets, as an integer value. Value depend on the type of interface, Ethernet network adapters have a default value of 1000 unless configured otherwise What: /sys/class/net//type Date: April 2005 KernelVersion: 2.6.12 Contact: netdev@vger.kernel.org Description: Indicates the interface protocol type as a decimal value. See include/uapi/linux/if_arp.h for all possible values. What: /sys/class/net//phys_switch_id Date: November 2014 KernelVersion: 3.19 Contact: netdev@vger.kernel.org Description: Indicates the unique physical switch identifier of a switch this port belongs to, as a string. What: /sys/class/net//phydev Date: May 2017 KernelVersion: 4.13 Contact: netdev@vger.kernel.org Description: Symbolic link to the PHY device this network device is attached to. What: /sys/class/net//carrier_changes Date: Mar 2014 KernelVersion: 3.15 Contact: netdev@vger.kernel.org Description: 32-bit unsigned integer counting the number of times the link has seen a change from UP to DOWN and vice versa What: /sys/class/net//carrier_up_count Date: Jan 2018 KernelVersion: 4.16 Contact: netdev@vger.kernel.org Description: 32-bit unsigned integer counting the number of times the link has been up What: /sys/class/net//carrier_down_count Date: Jan 2018 KernelVersion: 4.16 Contact: netdev@vger.kernel.org Description: 32-bit unsigned integer counting the number of times the link has been down What: /sys/class/net//threaded Date: Jan 2021 KernelVersion: 5.12 Contact: netdev@vger.kernel.org Description: Boolean value to control the threaded mode per device. User could set this value to enable/disable threaded mode for all napi belonging to this device, without the need to do device up/down. Possible values: == ================================== 0 threaded mode disabled for this dev 1 threaded mode enabled for this dev == ==================================