Tuesday, February 7, 2012

Using Ethtool to manage Ethernet Card

Ethtool is really a swiss army knife for diagnosing and managing and manipulating Network Card. I used it rather often. Here are some which I use more often.

Usage 1: ethtool eth0
# ethtool eth0

Settings for eth0:
        Supported ports: [ TP ]
        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: Yes
        Speed: 1000Mb/s
        Duplex: Full
        Port: Twisted Pair
        PHYAD: 1
        Transceiver: internal
        Auto-negotiation: on
        Supports Wake-on: d
        Wake-on: d
        Link detected: yes

Interesting information include "Link Detected Status", Duplex, Speed, Supported Ports etc. I particular find the Link Detection Usage one of my most used tool. :)

Usage 2: Checking of Ethernet Drivers Version
# ethtool -i eth0

driver: bnx2
version: 2.0.23b
firmware-version: bc 1.9.6
bus-info: 0000:03:00.0

Usage 3: Identify the Physical Network Card (Blink LED Port of NIC Card)
# ethtool -p eth0

Usage 4: Display Auto-negotiation, RX and TX of Network Card
# ethtool -a eth0

Pause parameters for eth0:
Autonegotiate:  on
RX:             on
TX:             on

Usage 5: Show offl-load property of Network Card.
# ethtool -k eth0

Cannot get device udp large send offload settings: Operation not supported
rx-checksumming: on
tx-checksumming: on
scatter-gather: on
tcp segmentation offload: on
udp fragmentation offload: off
generic segmentation offload: off
generic-receive-offload: off

For more information, do look at the excellent article on
  1. Ethtool man page
  2. 9 Linux ethtool Examples to Manipulate Ethernet Card (NIC Card)

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