Solarflare
Server
Adapter
User
Guide
Solarflare
Adapters
on
Linux
Issue
20
©
Solarflare
Communications
2017
75
NIC
Partitioning
Without
VLANs
Figure
9:
NIC
Partitioning
‐
without
VLANs
•
Configured
without
VLANs,
all
PFs
are
in
the
same
Ethernet
layer
2
broadcast
domain
i.e.
a
packet
broadcast
from
any
one
PF
would
be
received
by
all
other
PFs.
•
Transmitted
packets
go
directly
to
the
wire.
Packets
sent
between
PFs
are
routed
through
the
local
TCP/IP
stack
loopback
interface
without
touching
the
sfc
driver.
•
Received
broadcast
packets
are
replicated
to
all
PFs.
•
Received
multicast
packets
are
delivered
to
each
subscriber.
•
Received
unicast
packets
are
delivered
to
the
PF
with
a
matching
MAC
address.
Because
the
TCP/IP
stack
has
multiple
network
interfaces
on
the
same
broadcast
domain,
there
is
always
the
possibility
that
any
interface
could
respond
to
an
ARP
request.
To
avoid
this
the
user
should
use
arp_ignore=2
to
avoid
ARP
cache
pollution
ensuring
that
ARP
responses
are
only
sent
from
an
interface
if
the
target
IP
address
in
the
ARP
request
matches
the
interface
address
with
both
sender/receiver
IP
addresses
in
the
same
subnet.
•
To
set
arp_ignore
for
the
current
session:
echo
2
>/proc/sys/net/ipv4/conf/all/arp_ignore
•
To
set
arp_ignore
permanently
(does
not
affect
the
current
session),
add
the
following
line
to
the
/etc/sysctl.conf
file:
net.ipv4.conf.all.arp_ignore
=
2