Users Guide

Support for ECMP in host table
ECMP support in the L3 host table is available on the system. IPv6 /128 prefix route entries and IPv4 /32 prefix entries which are moved
to host table can have ECMP. For other platforms, only the IPv6 /128 prefix route entries is stored in the L3 host table without ECMP
support.
The software supports a command to program IPv6 /128 route prefixes in the host table.
The output of show IPv6 cam command has been enhanced to include the ECMP field in the Neighbor table of Ipv6 CAM. The sample
output is displayed as follows, which is similar to the prefix table.
The following is the portion of the example output:
Neighbor Mac-Addr Port Vid EC
------------------------------------- -------------------------
[ 132] 20::1 00:00:20:d5:ec:a0 Fo 1/4 0 1
[ 132] 20::1 00:00:20:d5:ec:a1 Fo 1/8 0 1
Support for moving /128 IPv6 Prefixes and /32 IPv4 Prefixes
The software supports a command to program IPv6 /128 route prefixes in the route table. You can define IPv6 /128 route prefixes in the
route table using the ipv6 unicast-host-routecommand. You can also define IPv4 /32 route prefixes in the host table using the
ipv4 unicast-host-routecommand.
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:
Dell#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
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Equal Cost Multi-Path (ECMP)