Ethtool
Linux network configuration tool
title: "Ethtool" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["linux-network-related-software", "linux-configuration-utilities", "linux-only-free-software", "free-network-related-software"] description: "Linux network configuration tool" topic_path: "technology/operating-systems" source: "https://en.wikipedia.org/wiki/Ethtool" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0
::summary Linux network configuration tool ::
::data[format=table title="Infobox software"]
| Field | Value |
|---|---|
| title | ethtool |
| author | David S. Miller |
| developer | Michal Kubecek |
| released | |
| latest release version | 6.15 |
| latest release date | |
| programming language | C |
| operating system | Linux |
| genre | Networking |
| license | GPLv2 |
| website | |
| :: |
| name = | title = ethtool | logo = | screenshot = | caption = | author = David S. Miller | developer = Michal Kubecek | released = | latest release version = 6.15 | latest release date = | programming language = C | operating system = Linux | genre = Networking | license = GPLv2 | website =
ethtool is the primary means in Linux kernel-based operating systems (primarily Linux and Android) for displaying and modifying the parameters of network interface controllers (NICs) and their associated device driver software from application programs running in userspace.
ethtool consists of two components, an API within the Linux kernel through which NICs can send and receive parameters through their device driver software, and a userspace API based on the Linux SIOCETHTOOL ioctl mechanism through which application programs can communicate with the kernel to send and receive NIC and NIC driver parameters.
Most Linux distributions provide a standard utility program called ethtool that can be used from a shell to control, or gather information from NICs using the ethtool userspace API. In the Information technology community, the term ethtool is usually used to refer to this utility program.
The ethtool userspace API can be accessed from programs written in the C and C++ programming languages through the C standard library or C++ standard library respectively.
Several scripting languages such as Perl and Python provide ethtool API bindings that allow programmers using these languages to write scripts that can control NIC's.
The macOS and FreeBSD 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 and flow control for Ethernet devices
- Control checksum offload and other hardware offload features, such as large receive offload and large send offload
- Control DMA ring sizes and interrupt moderation
- Control receive queue selection for multiqueue devices
- Upgrade firmware in flash memory
Examples
To display the current parameters of the first network port (): ::code[lang=console] $ ethtool eth0 Settings for eth0: Supported ports: [ TP MII ] 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 {{Cite web |date=2010-10-28 |title=9 Linux ethtool Examples to Manipulate Ethernet Card (NIC Card) |url=https://www.thegeekstuff.com/2010/10/ethtool-command/ |access-date=2020-11-14 |website=www.thegeekstuff.com}} ::
To configure it with the 1000 Mb/s speed and duplex, in 1000BASE-T: ::code[lang=console] $ ethtool -s eth0 speed 1000 duplex full autoneg off ::
To let the link light of the device eth0 flash for two minutes: ::code[lang=console] $ 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: ::code[lang=console] $ 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): ::code[lang=console] $ mii-tool -F 1000baseTx-FD eth0 $ mii-tool eth0: 1 000 Mbit, full duplex, link ok ::
References
References
- (2010-10-28). "9 Linux ethtool Examples to Manipulate Ethernet Card (NIC Card)".
- (September 2003). "Ethernet Auto-negotiation and Duplexing on Linux".
::callout[type=info title="Wikipedia Source"] This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page. ::