Discussion on load-balance and load-sharing

wfqk · ‎05-03-2015

Hi, I found a article, which discuss the difference between load-balance and load-sharing. I think the explanation is pretty good, please see below. But I still have a question: how can we decide to choose one the both balance in the production environment ? Thank you

"In short, load balancing tries to distribute traffic evenly over multiple paths, whereas, load sharing intends to do it (for the lack of a better term) equally. True load balancing is difficult to achieve. For example, let's say there were two links (100 mbps and 300 mpbs) and a router needed to send out 600 mbps of traffic. Load balancing would distribute the traffic evenly, sending 300 mbps on each link. On the contrary, load sharing would divide the traffic equally based on the available resources, sending 200 mbps on the slower link and 400 mbps on the faster one. "

Joseph W. Doherty · ‎05-04-2015

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That's not how Cisco uses the terms, and generically they are often used almost interchangeably.

Cisco uses load balancing as the catch all for how a single L3 device routes across multiple paths to the same destination. Equal metrics or equal actual load distribution are not required. Most often, load balancing will be discussed with ECMP, but unequal path loading balancing will include Cisco's proprietary IGPs, such as EIGRP.

Cisco uses load sharing when using multiple paths when a single L3 devices doesn't normally route across multiple paths or multiple L3 devices are involved. Cisco load sharing discussions usually revolve around BGP.

Generically, I would say load balancing has more of a dynamic aspect to it, i.e. something is trying to actively balance traffic across multiple paths, while load sharing might mean multiple paths are utilized but not actively dynamically balanced.

I'm unsure what's your question with a production environment.