Howto change network specific settings using ethtool in combination with NetworkManager
This document (7005304) is provided subject to the disclaimer at the end of this document.
Environment
openSUSE 11
openSUSE 11.1
openSUSE 11.2
Situation
- checksum offload (rx-checksumming,,tx-checksumming)
- segmentation offload (generic segmentation, tcp segmentation)
Resolution
Example: "ethtool -k eth0"
rx-checksumming: on
tx-checksumming: on
scatter-gather: off
tcp segmentation offload: off
udp fragmentation offload: off
generic segmentation offload: on
large receive offload: off
In order to change any options run ethtool -K [options] [dev]
Example: "ethtool -K eth0 rx off tx off tso off gso off
The result of running this would look like:
Cannot get device flags: Operation not supported
rx-checksumming: off
tx-checksumming: off
scatter-gather: off
tcp segmentation offload: off
udp fragmentation offload: off
generic segmentation offload: off
large receive offload: off
Any ethtool settings are lost as soon as the OS will be rebooted. With the traditional network configuration you can follow the steps documented in TID3344651. Running NetworkManager (most likely the case with Desktop PCs or Notebooks) you can place a shell script into the "/etc/NetworkManager/dispatcher.d" directory. NetworkManager will provides / pass on several paramaters like "ACTION", "INTERFACE", "STATUS" which can be used with a script called by NetworkManager. "ACTION" basically defines the event (pre-up, up, down, post-down) whereas "INTERFACE" and "STATUS" is pretty much self explaining. In order to turn off any offload settings as soon as "eth0" will run into the up status a simple script (mode 751 / owner: root / group: root) like the following can be used:
ACTION=$2
if [ "$ACTION" = "up"];then
/sbin/ethtool -K eth0 rx off tx off tso off gso off
echo "all segmentation offload settings have been switched off"
fi
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- Document ID:7005304
- Creation Date: 05-Feb-2010
- Modified Date:03-Mar-2020
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- SUSE Linux Enterprise Desktop
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