Users Guide

offset2 value (Optional) Specify the additional 2 bytes that must be extracted
from the start of the L4 header to be used for hash computation.
You must enter the offset as an even number. The offset range is
0 – 30 bytes from start of L4 header.
Default None
Command Modes CONFIGURATION mode
Command History
Version Description
9.10(0.1) Introduced on the S6010-ON and S4048T-ON.
9.8(1.0) Introduced on the Z9100–ON.
9.3(0.0) Introduced on the S6000 platform.
9.2(1.0) Introduced on the Z9500.
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
Flex Hash and Optimized Boot-Up 670