Cisco Viptela SDWAN EtherChannel Load Balancing

Cisco Viptela SDWAN EtherChannel Load Balancing

As you know that EtherChannel is basically used to load the traffic between the links. Lets see how and what methods we are using in Viptela SDWAN solution for load balance the traffic in EtherChannel.

Load-balancing can be configured globally for all port channels or directly for specific port channels. Unless you explicitly configure load balancing for a port channel, the global configuration applies. Global configurations are overridden by port-channel configurations.

In Cisco Viptela SDWAN, there are two types of Load balancing techniques in EtherChannel and these are Flow based or VLAN Based.

Fig 1.1- EtherChannel in Cisco Viptela SDWAN

Flow Based EtherChannel
A default load-balancing method is flow-based load balancing, which is enabled at the global level by default.

Flow-based load balancing recognizes various traffic flows based on the important data packet elements. For instance, a flow can be recognized using the source and destination IP addresses of IPv4.

The various data traffic flows are then assigned to the various port channel member links. Data traffic for a flow is transferred across the designated member connection following the completion of the mapping. The flow mapping is dynamic and alters whenever a member link to whom a flow is associated experiences a change in status. 

When new or removed member links are introduced, the flow mapping changes.

VLAN-Based Load Balancing
You can establish static assignment of user traffic, as indicated by a VLAN ID, to a specific member link of an EtherChannel using VLAN-based load balancing. A primary and secondary link can both have VLAN sub interfaces manually assigned to them. 

Without regard to vendor equipment capabilities, this feature enables load balancing to downstream equipment and offers failover protection by diverting traffic to the backup member link in the event of a primary link failure. 

Up to 16 bundles can be supported per chassis for member linkages.