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			'''''[https://it-arts.net/index.php/Category:Wiki Return to Wiki Index]'''''


	== Common Commands ==		== Common Commands ==

Admin at 17:42, 6 January 2026

2026-01-06T17:42:45Z

← Older revision		Revision as of 17:42, 6 January 2026
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	If you're experiencing slow network speeds or high latency, consider these steps:		If you're experiencing slow network speeds or high latency, consider these steps:

	====Increase Ring Buffer Size** to handle more traffic:		==== Increase Ring Buffer Size** to handle more traffic:
	<nowiki>		<nowiki>
	ethtool -G eth0 rx 4096 tx 4096</nowiki>		ethtool -G eth0 rx 4096 tx 4096</nowiki>

	====Check for Dropped Packets ====		==== Check for Dropped Packets ====
	Use `ethtool -S eth0` to check if there are any dropped packets that could indicate network issues.		Use `ethtool -S eth0` to check if there are any dropped packets that could indicate network issues.

	====Disable Offloading Features** temporarily to test if the offload mechanisms are affecting performance:		==== Disable Offloading Features ====
			Temporarily to test if the offload mechanisms are affecting performance:
	<nowiki>		<nowiki>
	ethtool -K eth0 tx off rx off</nowiki>		ethtool -K eth0 tx off rx off</nowiki>

	====Check Interface Errors ====		==== Check Interface Errors ====
	Use the following command to check for errors on the interface:		Use the following command to check for errors on the interface:
	<nowiki>		<nowiki>

Admin: Created page with "Category:Wiki == Common Commands == === Display Information === To display detailed information about a network interface: ethtool eth0 This command outputs various statistics and properties such as speed, duplex mode, supported features, and driver information. === Display Driver Information === To display the driver details for a specific interface: ethtool -i eth0 This provides the driver version, firmware version, and su..."

2026-01-06T17:41:33Z

Created page with "Category:Wiki == Common Commands == === Display Information === To display detailed information about a network interface: <nowiki> ethtool eth0</nowiki> This command outputs various statistics and properties such as speed, duplex mode, supported features, and driver information. === Display Driver Information === To display the driver details for a specific interface: <nowiki> ethtool -i eth0</nowiki> This provides the driver version, firmware version, and su..."

New page

[[Category:Wiki]]

== Common Commands ==

=== Display Information ===
To display detailed information about a network interface:
<nowiki>
ethtool eth0</nowiki>

This command outputs various statistics and properties such as speed, duplex mode, supported features, and driver information.

=== Display Driver Information ===
To display the driver details for a specific interface:
<nowiki>
ethtool -i eth0</nowiki>

This provides the driver version, firmware version, and supported features.

=== Check Link Status ===
To check if the link is up or down on a specific interface:
<nowiki>
ethtool eth0 | grep "Link detected"</nowiki>

This outputs whether the link is up or down.

=== Change Speed and Duplex Mode ===
To set a specific speed and duplex mode for an interface:
<nowiki>
ethtool -s eth0 speed 1000 duplex full autoneg off</nowiki>

This command sets the speed to 1000Mbps, full duplex, and disables auto-negotiation.

=== Enable/Disable Auto-Negotiation ===
To disable or enable auto-negotiation:
<nowiki>
ethtool -s eth0 autoneg off</nowiki>

To enable auto-negotiation:
<nowiki>
ethtool -s eth0 autoneg on</nowiki>

=== Set Wake-on-LAN Options ===
To configure Wake-on-LAN (WoL) settings:
<nowiki>
ethtool -s eth0 wol g</nowiki>

This enables WoL for magic packets. To disable WoL:
<nowiki>
ethtool -s eth0 wol d</nowiki>

=== Set Ring Buffer Size ===
To adjust the ring buffer size (useful for high throughput environments):
<nowiki>
ethtool -G eth0 rx 4096 tx 4096</nowiki>

This sets the receive and transmit ring buffer sizes to 4096.

=== Display Interface Statistics ===
To display statistics such as packet errors, drops, and other counters:
<nowiki>
ethtool -S eth0</nowiki>

This shows statistics such as `rx_dropped`, `tx_dropped`, `rx_errors`, `tx_errors`, etc.

== Advanced Configuration ==

=== Change MAC Address ===
To display the current MAC address of an interface:

<nowiki>
ethtool -P eth0</nowiki>

To change the MAC address temporarily:

<nowiki>
ethtool -s eth0 hw ether XX:XX:XX:XX:XX:XX</nowiki>
Replace `XX:XX:XX:XX:XX:XX` with the desired MAC address.

=== Enable/Disable Offload Features ===
To disable TX and RX checksum offload:
<nowiki>
ethtool -K eth0 tx off rx off</nowiki>
This command disables the offloading of checksum calculations for transmitted and received packets.

=== Display and Modify Driver Settings ===
To display the driver settings for an interface:
<nowiki>
ethtool -d eth0</nowiki>
This command shows the detailed driver settings for debugging purposes.

=== Interrupt Coalescing ===
To adjust interrupt coalescing settings (to improve performance or reduce CPU usage):
<nowiki>
ethtool -C eth0 rx-usecs 1000 tx-usecs 1000</nowiki>
This sets the coalescing time for both receive and transmit interrupts.

=== View Supported Features ===
To view the supported features of the network interface:
<nowiki>
ethtool -i eth0</nowiki>
This will show the available driver features, including offloading capabilities and other hardware support.

== Security Concepts ==

=== Disabling Unnecessary Features ===
Disabling features such as Wake-on-LAN and Auto-Negotiation is essential to reduce attack surfaces on your system, especially when these features are not in use.

- **Disable Wake-on-LAN** if not required:
<nowiki>
ethtool -s eth0 wol d</nowiki>

- **Disable Auto-Negotiation** to avoid unexpected changes in network settings:
<nowiki>
ethtool -s eth0 autoneg off</nowiki>

- **Disable checksum offload** for debugging purposes, but note that this might impact performance:
<nowiki>
ethtool -K eth0 tx off rx off</nowiki>

These settings can be used to minimize vulnerabilities, especially in environments with strict security policies.

== Troubleshooting ==

=== Interface Shows as "Disconnected" ===
If the network interface shows as disconnected even when the physical connection is fine, try the following steps:

==== Check the Link Status ====
<nowiki>
ethtool eth0 | grep "Link detected"</nowiki>
If it shows "no," the issue could be with the cable, switch, or NIC.

==== Force Link Settings ====
Sometimes, forcing the link settings (speed, duplex) can solve the issue:
<nowiki>
ethtool -s eth0 speed 1000 duplex full autoneg off</nowiki>

==== Check Network Interface Driver ====
Ensure that the driver is correctly installed and supports the network interface:
<nowiki>
ethtool -i eth0</nowiki>

==== Reboot the Interface ====
Resetting the interface can sometimes resolve connection issues:
<nowiki>
ifdown eth0 && ifup eth0</nowiki>

=== Low Network Performance ===
If you're experiencing slow network speeds or high latency, consider these steps:

====Increase Ring Buffer Size** to handle more traffic:
<nowiki>
ethtool -G eth0 rx 4096 tx 4096</nowiki>

====Check for Dropped Packets ====
Use `ethtool -S eth0` to check if there are any dropped packets that could indicate network issues.

====Disable Offloading Features** temporarily to test if the offload mechanisms are affecting performance:
<nowiki>
ethtool -K eth0 tx off rx off</nowiki>

====Check Interface Errors ====
Use the following command to check for errors on the interface:
<nowiki>
ethtool -S eth0</nowiki>

These steps should help identify if there are hardware or driver-related issues affecting the performance.

== Useful Links ==
* [ethtool Manual Page](https://man7.org/linux/man-pages/man8/ethtool.8.html)
* [Linux Ethernet Drivers](https://www.kernel.org/doc/html/latest/networking/)
* [ethtool GitHub Repository](https://github.com/torvalds/linux/tree/master/tools/net/ethtool)
* [Wake-on-LAN Specifications](https://en.wikipedia.org/wiki/Wake-on-LAN)

ETHTOOL - Base Documentation - Revision history

Admin: Text replacement - "Category:Wiki" to "Category:Wiki '''''[https://it-arts.net/index.php/Category:Wiki Return to Wiki Index]''''' "

Admin at 17:42, 6 January 2026