Dell Intel PRO Family of Adapters - Manual (Page 95)

Parameter Name Valid
Range/Settings
Default Description
-N --config-nfc
Configures the receive network flow classification.
rx-flow-hash tcp4|ud-
p4|ah4|esp4|sctp4|tcp6|udp6|ah6|esp6|sctp6
m|v|t|s|d|f|n|r...
Configures the hash options for the specified network traffic
type.
udp4
UDP over IPv4
udp6
UDP over IPv6
f
Hash on bytes 0 and 1 of the Layer 4 header of the rx packet.
n
Hash on bytes 2 and 3 of the Layer 4 header of the rx packet.
The following is an example using udp4 (UDP over IPv4):
To include UDP port numbers in RSS hashing run:
ethtool -N eth1 rx-flow-hash udp4 sdfn
To exclude UDP port numbers from RSS hashing run:
ethtool -N eth1 rx-flow-hash udp4 sd
To display UDP hashing current configuration run:
ethtool -n eth1 rx-flow-hash udp4
The results of running that call will be the following, if UDP hash-
ing is enabled:
UDP over IPV4 flows use these fields for com-
puting Hash flow key:
IP SA
IP DA
L4 bytes 0 & 1 [TCP/UDP src port]
L4 bytes 2 & 3 [TCP/UDP dst port]
The results if UDP hashing is disabled would be:
UDP over IPV4 flows use these fields for com-
puting Hash flow key:
IP SA
IP DA
The following two parameters impact Flow Director: FdirPballoc
and AtrSampleRate.
FdirPballoc 0 - 2 0 (64k) Flow Allocated Packet Buffer Size.
0 = 64k
1 = 128k
2 = 256k
AtrSampleRate 1 - 100 20 Software ATR Tx Packet Sample Rate. For example, when set
to 20, every 20th packet is sampled to determine if the packet
will create a new flow.