Users Guide

load-balance exhash
Specify the parameters for the Flex Hash mechanism, such as whether IPv4 or IPv6 packets must be subject to Flex Hash functionality, a
unique protocol number, the oset of hash elds from the start of the L4 header to be used for hash calculation, and a meaningful
description to associate the protocol number with the name.
Syntax
load-balance flexhash ipv4/ipv6 ip-proto <protocol number> <description string>
offset1 <offset1 value> [offset2 <offset2 value>]
To disable the Flex hash settings, use the no load-balance flexhash ipv4/ipv6 ip-proto
protocol number command.
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 Description
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 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-
Flex Hash and Optimized Boot-Up 589