User Manual

Features Overview and ConfigurationRev 2.3-1.0.1
Mellanox Technologies
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3.1.4 Ethtool
ethtool is a standard Linux utility for controlling network drivers and hardware, particularly for
wired Ethernet devices. It can be used to:
• Get identification and diagnostic information
• Get extended device statistics
• Control speed, duplex, autonegotiation and flow control for Ethernet devices
• Control checksum offload and other hardware offload features
• Control DMA ring sizes and interrupt moderation
The following are the ethtool supported options:
Table 3 - ethtool Supported Options
Options Description
ethtool -i eth<x> Checks driver and device information.
For example:
#> ethtool -i eth2
driver: mlx4_en (MT_0DD0120009_CX3)
version: 2.1.6 (Aug 2013)
firmware-version: 2.30.3000
bus-info: 0000:1a:00.0
ethtool -k eth<x> Queries the stateless offload status.
ethtool -K eth<x> [rx on|off] [tx
on|off] [sg on|off] [tso on|off] [lro
on|off] [gro on|off] [gso on|off]
[rxvlan on|off]
Sets the stateless offload status.
TCP Segmentation Offload (TSO), Generic Segmentation
Offload (GSO): increase outbound throughput by reducing
CPU overhead. It works by queuing up large buffers and
letting the network interface card split them into separate
packets.
Large Receive Offload (LRO): increases inbound through-
put of high-bandwidth network connections by reducing
CPU overhead. It works by aggregating multiple incoming
packets from a single stream into a larger buffer before
they are passed higher up the networking stack, thus
reducing the number of packets that have to be processed.
LRO is available in kernel versions < 3.1 for untagged
traffic.
Note: LRO will be done whenever possible. Otherwise
GRO will be done. Generic Receive Offload (GRO) is
available throughout all kernels.
Hardware Vlan Striping Offload (rxvlan): When enabled
received VlAN traffic will be stripped from the VLAN tag
by the hardware.
ethtool -c eth<x> Queries interrupt coalescing settings.