Connectivity Guide

Table Of Contents
NOTE: An ecmp-group index is generated automatically for each unique ecmp-group when you configure multipath routes
to the same network. The system can generate a maximum of 512 unique ecmp-groups. The ecmp-group indices are
generated in even numbers (0, 2, 4, 6... 1022) and are for information only.
You can configure ecmp-group with id 2 for link bundle monitoring. This ecmp-group is different from the ecmp-group index
2 that is created by configuring routes and is automatically generated. These two ecmp-groups are not related in any way.
DellEMC(conf-ecmp-group-5)#show config
!
ecmp-group 5
interface tengigabitethernet 1/2
interface tengigabitethernet 1/3
link-bundle-monitor enable
DellEMC(conf-ecmp-group-5)#
RTAG7
RTAG7 is a hashing algorithm that load balances the traffic within a trunk group in a controlled manner. In order to effectively
increase the bandwidth of the LAG/Equal Cost Multiple Path routes, traffic is balanced across the member links. The balancing
is performed by using the RTAG7 hashing, which is designed to have the member links used efficiently as the traffic profile gets
more diverse.Hashing-based load balancing is used in the following applications:
L3 ECMP
LAGs
HiGig trunking
The RTAG7 hash scheme generates a hash that consists of the following two portions:
The first portion is primarily generated from packet headers to identify micro-flows in the traffic. The Parameters that are
considered for hash computations by default in RTAG7 hashing is shown in the given example:
DellEMC#show load-balance
Load-Balancing Configuration For LAG & ECMP:
--------------------------------------------
IPV4 Load Balancing Enabled
IPV4 FIELDS : source-ipv4 dest-ipv4 vlan protocol L4-source-port L4-dest-port
IPV6 Load Balancing Enabled
IPV6 FIELDS : source-ipv6 dest-ipv6 vlan protocol L4-source-port L4-dest-port
Mac Load Balancing Enabled
MAC FIELDS : source-mac dest-mac vlan ethertype
Load Balancing Configuration for tunnels
ipv4-over-ipv4 Payload header
ipv4-over-ipv6 Payload header
ipv6-over-ipv6 Payload header
ipv6-over-ipv4 Payload header
ipv4-over-gre-ipv4 Payload header
ipv6-over-gre-ipv4 Payload header
ipv4-over-gre-ipv6 Payload header
ipv6-over-gre-ipv6 Payload header
mac-in-mac header based hashing is disabled
TcpUdp Load Balancing Enabled
DellEMC(conf)#
Packet Header parameters for the first portion of the RTAG7 hash can be controlled. By default, all the listed parameters
from the Packet header are considered for hash computation. Few parameters [on demand] can be removed using the given
CLIs.
DellEMC(conf)#load-balance ?
flexhash Enable flexhash based on IP Protocol
ingress-port Option to Source Port Id for ECMP/LAG hashing
ip-selection Set the IPV4 key fields to use in hash computation(default =
source-ip dest-ip vlan protocol L4-source-port L4-dest-port)
ipv6-selection Set the IPV6 key fields to use in hash computation(default =
source-ipv6 dest-ipv6 vlan protocol L4-source-port L4-dest-port)
Equal Cost Multi-Path (ECMP)
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