Tcp Checksum Offload - Hitachi Compute Blade 2000 User Manual

Confirm that the OS privilege is set as shown below.
# ls -l /etc/sysconfig/modules/acpiphp.modules
-rwxr-xr-x 1 root root 35 mm dd hh:mm
/etc/sysconfig/modules/acpiphp.modules
2 Load the acpiphp module.
Perform acpiphp.modules created in Step 1.
# /etc/sysconfig/modules/acpiphp.modules
Check if the acpiphp module has been loaded. This step is required once when
the acpiphp.modules are created. Next time, acpiphp will be automatically
loaded at the OS boot.
# /sbin/lsmod | grep acpiphp
acpiphp 58713 0

TCP checksum offload

With TCP (Transmission Checksum Protocol) enabled, which checks TCP packets in
a LAN controller, failure in the LAN controller may cause packet data to be destroyed.
Target device drivers:
•
e1000 e driver
•
igb driver
TCP checksum offload is set by specifying parameters of tx (in transmission) and rx
(in reception) to the argument of the ethtool command. The following describes
values of tx/rx parameters and the format.
values: off (disabled) or on (enabled)
Disable TCP checksum offload in both transmission and reception using the ethtool command. Add
the ethtool command to /sbin/ifup-pre-local as shown below, and restart the OS. The
settings will be automatically specified at the OS restart.
Example: When disabling two LAN controllers, add the following line to /sbin/ifup-pre-local
assuming that Linux recognizes each of them as network devices eth0 and eth1.
if [ "${1}" == "ifcfg-eth0" ]; then
/sbin/ethtool -K eth0 rx off
/sbin/ethtool -K eth0 tx off
fi
if [ "${1}" == "ifcfg-eth1" ]; then
/sbin/ethtool -K eth1 rx off
/sbin/ethtool -K eth1 tx off
fi
If the /sbin/ifup-pre-local file does not exist, create a new one with the file privilege 755
and add the setting above. If the file exists, add the setting above to the file. Then restart the OS or
restart the network device to enable the setting.
To enable TCP checksum offload, use the procedure by replacing values of tx/rx
parameters "off" with "on".
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