Solarflare
Server
Adapter
User
Guide
Solarflare
Adapters
on
Linux
Issue
20
©
Solarflare
Communications
2017
71
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
its
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:
ethtool
‐
s
ethX
advertise
0x20
•
Set
autonegotiation
advertised
speed
10G:
ethtool
‐
s
ethX
advertise
0x1000
•
Set
autonegotiation
advertised
speeds
1G
and
10G:
ethtool
‐
s
ethX
advertise
0x1020
•
Identify
interface
auto
negotiation
pause
frame
setting:
ethtool
‐
a
ethX
•
Configure
auto
negotiation
of
pause
frames:
ethtool
‐
A
ethX
autoneg
on
[rx
on|off]
[tx
on|off]
NOTE:
Due
to
a
limitation
in
ethtool,
when
auto
‐
negotiation
is
enabled,
the
user
must
specify
both
speed
and
duplex
mode
or
speed
and
set
an
advertise
mask
otherwise
speed
configuration
will
not
function.