Issue 11
© Solarflare Communications 2014
49
Solarflare Server Adapter
User Guide
3.10 Hardware Timestamps
The Solarflare Flareon SFN7000 series adapters can support hardware timestamping for all received
network packets.
The Linux kernel must support the SO_TIMESTAMPING socket option (2.6.30+) therefore hardware
packet timestamping is not supported on RHEL 5.
For more information about using the kernel timestamping API, users should refer to the Linux
documentation:
http://lxr.linux.no/linux/Documentation/networking/timestamping.txt
3.11 Configuring the Solarflare Adapter
The general command for ethtool is as follows:
ethtool <-option> <ethX>
Where X is the identifier of the interface. Note that root access will be required to configure adapter
settings. Refer to the Linux online manual (
man ethtool
) for details of the options that are
available for ethtool.
Configuring Speed and Modes
Solarflare adapters by default automatically negotiate the connection speed to the maximum
supported by the link partner. On the 10GBASE-T adapters “auto” instructs the adapter to negotiate
the highest speed supported in common with it’s link partner. On SFP+ adapters, “auto” instructs the
adapter to use the highest link speed supported by the inserted SFP+ module. On 10GBASE-T and
SFP+ adapters, any other value specified will fix the link at that speed, regardless of the capabilities
of the link partner, which may result in an inability to establish the link. Dual speed SFP+ modules
operate at their maximum (10G) link speed unless explicitly configured to operate at a lower speed
(1G).
The following commands demonstrate ethtool to configure the network adapter Ethernet settings.
Identify interface configuration settings:
ethtool ethX
Set link speed:
ethtool -s ethX speed 1000|100
To return the connection speed to the default auto-negotiate, enter:
ethtool -s <ethX> autoneg on
Configure auto negotiation:
ethtool -s ethX autoneg [on|off]
Set auto negotiation advertised speed 1G: