Dell C9000 series, Reference Manual

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Usage Information With the introduction of various overlay technologies such as network virtualization
using generic routing encapsulation (NVGRE) segments and Routable Remote Direct
Memory Access (RRDMA) over Converged Ethernet (RRoCE), information related to a
traffic flow is contained in the L4 header. The fields in the L2 and L3 headers are not
sufficient to distinguish the flows. Therefore, the fields in the L4 header are processed
when hashing is performed for packets over LAG and ECMP links. The Flex Hash
functionality enables you to configure a packet search key and matches packets based
on the search key. When a packet matches the search key, two 16-bit hash fields are
extracted from the start of the L4 header and provided as inputs (bins 2 and 3) for
RTAG7 hash computation. You must specify the offset of hash fields from the start of
the L4 header, which contains a flow identification field.
You can cause the system to include the fields present at the offsets that you define
(from the start of the L4 header) as a part of LAG and ECMP computation. Also, you can
specify whether the IPv4 or IPv6 packets must be operated with the Flex Hash
mechanism.
Example
Dell(conf)# load-balance flexhash ipv4 ip-proto 1 desc offset1 1
offset2 2
load-balance ingress-port enable
Enable the Flex hash functionality. This utility is supported on the C9000 platform.
Syntax
load-balance ingress-port enable
To disable the Flex hash capability, use the no version of this command.
Default None
Command Modes CONFIGURATION mode
Command History This guide is platform-specific. For command information about other platforms, refer
to the relevant Dell Networking OS Command Reference Guide .
The following is a list of the Dell Networking OS version history for this command.
Version Description
9.9.(0.0) Introduced on the C9010.
9.3(0.0) Introduced on the S6000 platform.
Usage Information Flex hash uses the RTAG7 bins 2 and 3 (overlay bins). These bins must be enabled for
Flex hash to be configured. These bins contain the source module and source port
information. These bins are disabled by default in releases of Dell Networking OS earlier
than Release 9.3.0.0. The default behavior of disabling of these bins occurs because of
incorrect egress port information that would otherwise be displayed in the output of
the diagnostic show command of
show ip flow
.
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