Service Manual

Parameters
ipv4 Denotes whether Flex Hash needs to be enabled for IPv4 packets.
ipv6 Denotes whether Flex Hash needs to be enabled for IPv6 packets.
protocol number Represents the Outer IPv4 protocol eld in case of IPv4 packets, and the Outer
IPv6 next header eld in case of IPv6 packets.
The ipv4/ipv6 keyword and the IP protocol value are used as keys to identify if a
duplicate ex hash conguration is already present. Duplicate ex hash
conguration is not possible. To change an existing ex hash conguration, you
must delete the existing ex hash attribute and congure the ex attribute afresh.
description string A description string is followed by the protocol number to enable you to associate
the protocol number with the protocol name in an easily-identiable way. For
example, for a protocol number of 254, you can specify the description as RRoCE.
oset1 value Specify the byte oset from the start of the L4 header from which the 2-byte data
is extracted and be used in hash computation. You must enter the oset as an even
number. The oset range is 0 – 30 bytes from start of L4 header.
oset2 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 oset as an
even number. The oset range is 0 – 30 bytes from start of L4 header.
Default None
Command Modes CONFIGURATION mode
Command History
Version 9.3(0.0) Introduced on the S6000 platform.
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 trac ow is contained in the L4 header. The elds in the L2 and
L3 headers are not sucient to distinguish the ows. Therefore, the elds in the L4 header are processed
when hashing is performed for packets over LAG and ECMP links. The Flex Hash functionality enables you
to congure a packet search key and matches packets based on the search key. When a packet matches
the search key, two 16-bit hash elds 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 oset of hash elds from the start of the
L4 header, which contains a ow identication eld.
You can cause the system to include the elds present at the osets that you dene (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
512
Flex Hash and Optimized Boot-Up