ethtool is the primary means in

Linux kernel The Linux kernel is a Free and open-source software, free and open source Unix-like kernel (operating system), kernel that is used in many computer systems worldwide. The kernel was created by Linus Torvalds in 1991 and was soon adopted as the k ...

-based

operating system An operating system (OS) is system software that manages computer hardware and software resources, and provides common daemon (computing), services for computer programs. Time-sharing operating systems scheduler (computing), schedule tasks for ...

s (primarily

Linux Linux ( ) is a family of open source Unix-like operating systems based on the Linux kernel, an kernel (operating system), operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically package manager, pac ...

and Android) for displaying and modifying the parameters of

network interface controller A network interface controller (NIC, also known as a network interface card, network adapter, LAN adapter and physical network interface) is a computer hardware component that connects a computer to a computer network. Early network interface ...

s (NICs) and their associated

device driver In the context of an operating system, a device driver is a computer program that operates or controls a particular type of device that is attached to a computer or automaton. A driver provides a software interface to hardware devices, enabli ...

software from application programs running in

userspace A modern computer operating system usually uses virtual memory to provide separate address spaces or regions of a single address space, called user space and kernel space. This separation primarily provides memory protection and hardware prote ...

. ethtool consists of two components, an

API An application programming interface (API) is a connection between computers or between computer programs. It is a type of software interface, offering a service to other pieces of software. A document or standard that describes how to build ...

within the Linux kernel through which NICs can send and receive parameters through their device driver software, and a

API based on the Linux SIOCETHTOOL

ioctl In computing, ioctl (an abbreviation of input/output control) is a system call for device-specific input/output operations and other operations which cannot be expressed by regular file semantics. It takes a parameter specifying a request code; ...

mechanism through which application programs can communicate with the kernel to send and receive NIC and NIC driver parameters. Most

Linux distribution A Linux distribution, often abbreviated as distro, is an operating system that includes the Linux kernel for its kernel functionality. Although the name does not imply product distribution per se, a distro—if distributed on its own—is oft ...

s provide a standard

utility program Utility software is a program specifically designed to help manage and tune system or application software. It is used to support the computer infrastructure - in contrast to application software, which is aimed at directly performing tasks that b ...

calle
ethtool
that can be used from a

shell Shell may refer to: Architecture and design * Shell (structure), a thin structure ** Concrete shell, a thin shell of concrete, usually with no interior columns or exterior buttresses Science Biology * Seashell, a hard outer layer of a marine ani ...

to control, or gather information from NICs using the ethtool

API. In the

Information technology Information technology (IT) is a set of related fields within information and communications technology (ICT), that encompass computer systems, software, programming languages, data processing, data and information processing, and storage. Inf ...

community, the term ''ethtool'' is usually used to refer to this utility program. The ethtool

API can be accessed from programs written in the C and C++

programming language A programming language is a system of notation for writing computer programs. Programming languages are described in terms of their Syntax (programming languages), syntax (form) and semantics (computer science), semantics (meaning), usually def ...

s through the

C standard library The C standard library, sometimes referred to as libc, is the standard library for the C (programming language), C programming language, as specified in the ISO C standard.International Organization for Standardization, ISO/International Electrote ...

C++ standard library The C standard library, sometimes referred to as libc, is the standard library for the C programming language, as specified in the ISO C standard.ISO/ IEC (2018). '' ISO/IEC 9899:2018(E): Programming Languages - C §7'' Starting from the origina ...

respectively. Several

scripting language In computing, a script is a relatively short and simple set of instructions that typically automation, automate an otherwise manual process. The act of writing a script is called scripting. A scripting language or script language is a programming ...

s such as

Perl Perl is a high-level, general-purpose, interpreted, dynamic programming language. Though Perl is not officially an acronym, there are various backronyms in use, including "Practical Extraction and Reporting Language". Perl was developed ...

and

Python Python may refer to: Snakes * Pythonidae, a family of nonvenomous snakes found in Africa, Asia, and Australia ** ''Python'' (genus), a genus of Pythonidae found in Africa and Asia * Python (mythology), a mythical serpent Computing * Python (prog ...

provide ethtool API bindings that allow programmers using these languages to write scripts that can control NIC's. The

macOS macOS, previously OS X and originally Mac OS X, is a Unix, Unix-based operating system developed and marketed by Apple Inc., Apple since 2001. It is the current operating system for Apple's Mac (computer), Mac computers. With ...

and

FreeBSD FreeBSD is a free-software Unix-like operating system descended from the Berkeley Software Distribution (BSD). The first version was released in 1993 developed from 386BSD, one of the first fully functional and free Unix clones on affordable ...

operating systems provide utility programs that have a user interface similar to the Linux ethtool utility, but that use fundamentally different APIs to communicate with their operating system kernels and NIC's.

Usage

The command is useful for: * Identification and diagnosis of Ethernet devices * Extended Ethernet devices statistics * Control speed, duplex,

autonegotiation Autonegotiation is a signaling mechanism and procedure used by Ethernet over twisted pair by which two connected devices choose common transmission parameters, such as speed, Duplex_(telecommunications), duplex mode, and Flow_control_(data), flow ...

and flow control for Ethernet devices * Control

checksum A checksum is a small-sized block of data derived from another block of digital data for the purpose of detecting errors that may have been introduced during its transmission or storage. By themselves, checksums are often used to verify dat ...

offload and other hardware offload features, such as

large receive offload TCP offload engine (TOE) is a technology used in some network interface cards (NIC) to offload processing of the entire TCP/IP stack to the network controller. It is primarily used with high-speed network interfaces, such as gigabit Ethernet and ...

and

large send offload TCP offload engine (TOE) is a technology used in some network interface cards (NIC) to offload processing of the entire TCP/IP stack to the network controller. It is primarily used with high-speed network interfaces, such as gigabit Ethernet and 1 ...

* Control DMA ring sizes and interrupt moderation * Control receive queue selection for multiqueue devices * Upgrade

firmware In computing Computing is any goal-oriented activity requiring, benefiting from, or creating computer, computing machinery. It includes the study and experimentation of algorithmic processes, and the development of both computer hardware, h ...

flash memory Flash memory is an Integrated circuit, electronic Non-volatile memory, non-volatile computer memory storage medium that can be electrically erased and reprogrammed. The two main types of flash memory, NOR flash and NAND flash, are named for t ...

Examples

To display the current parameters of the first network port (): $ ethtool eth0 Settings for eth0: Supported ports:

TP MII TP may refer to: Arts and entertainment Music * Test pressing, of a vinyl record * Tonic parallel (Tp and tP), in music theory * ''TP'' (Teddy Pendergrass album), 1980 * ''TP'' (Tony Parker album), 2007 * Tonus Peregrinus (vocal ensemble), a ...

Supported link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full Supports auto-negotiation: Yes Advertised link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full Advertised auto-negotiation: No Speed: 100Mb/s Duplex: Full Port: MII PHYAD: 1 Transceiver: internal Auto-negotiation: off Supports Wake-on: g Wake-on: g Current message level: 0x00000007 (7) Link detected: yes To configure it with the 1000 Mb/s speed and duplex, in

1000BASE-T In computer networking, Gigabit Ethernet (GbE or 1 GigE) is the term applied to transmitting Ethernet frames at a rate of a gigabit per second. The most popular variant, 1000BASE-T, is defined by the IEEE 802.3ab standard. It came into use i ...

: $ ethtool -s eth0 speed 1000 duplex full autoneg off To let the link light of the device eth0 flash for two minutes: $ ethtool -p eth0 120 To print the driver info of the interface eth0: $ ethtool -i eth0 driver: mlx5_core version: 4.9-2.2.4 firmware-version: 14.28.2006 (MT_2420110034) expansion-rom-version: bus-info: 0000:65:00.1 supports-statistics: yes supports-test: yes supports-eeprom-access: no supports-register-dump: no supports-priv-flags: yes

mii-tool

mii-tool is an older program performing a similar function to ethtool. Since 2003, it's considered obsolete and replaced by ethtool.

Example

To display the current parameters: $ mii-tool eth0: no autonegotiation, 100baseTx-HD, link ok To force the network speed to 1 Gbit/s, and the ''duplex'' in ''full'' on the port 1 (eth0): $ mii-tool -F 1000baseTx-FD eth0 $ mii-tool eth0: 1 000 Mbit, full duplex, link ok

References

External links