Connectivity Guide

Usage Information The path with the highest weight value is preferred in the best-path selection process. The no version of this
command resets the value to the default.
Example
OS10(conf-router-bgp-neighbor)# weight 4096
Supported Releases 10.3.0E or later
Equal cost multi-path
ECMP is a routing technique where next-hop packet forwarding to a single destination occurs over multiple best paths. When you enable
ECMP, OS10 uses a hash algorithm to determine the next-hop. The hash algorithm makes hashing decisions based on values in various
packet elds and internal values.
Congure the hash algorithm in CONFIGURATION mode.
hash-algorithm ecmp crc
NOTE: The S5148F-ON platform supports only the crc hash algorithm.
Change hash algorithm
OS10(config)# hash-algorithm ecmp crc
Load balancing
To increase bandwidth, trac is balanced across member links. RTAG7 is a hash algorithm that load balances trac within a trunk group in
a controlled manner. RTAG7 balances trac to more eectively use member links as trac gets more diverse.
RTAG7 generates a hash that consists of two parts:
• The rst part generates from packet headers to identify micro-ows in trac. By default, all listed parameters are enabled for load
balancing except the ingress port.
OS10# show load-balance
Load-Balancing Configuration For LAG and ECMP:
----------------------------------------------
IPV4 Load Balancing : Enabled
IPV6 Load Balancing : Enabled
MAC Load Balancing : Enabled
TCP-UDP Load Balancing : Enabled
Ingress Port Load Balancing : Disabled
IPV4 FIELDS : source-ip destination-ip protocol vlan-id l4-destination-port l4-source-port
IPV6 FIELDS : source-ip destination-ip protocol vlan-id l4-destination-port l4-source-port
MAC FIELDS : source-mac destination-mac ethertype vlan-id
TCP-UDP FIELDS: l4-destination-port l4-source-port
• The second part generates from the static physical conguration such as the ingress and egress port numbers.
To generate load balancing based on any parameters, change the hash eld using the load-balance command.
Resilient hashing
To increase bandwidth and for load balancing, trac distributes across the next hops of an ECMP group or member ports of a port
channel. OS10 uses a hash algorithm to determine a hash key. The egress port in a port channel or the next hop in an ECMP group is
selected based on the hash key modulo the number of ports in a port channel or next hops in an ECMP group, respectively. When a
member link goes down or a new member link is added, the trac ows remap based on the new hash result.
Layer 3
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