So, I've been looking through some of the literature I was sent about iscsi failover for open-e, and some of it mentions something called a "ping-node."

Is this required? How is a ping node set up? Is this a common feature of high-end switches?

One important thing is that this might lead to a "single point of failure." Is this true? If a ping node is required for auto failover, can a ping-node have a hot spare of some sort, so there wouldn't be a single point of failure?

We have customers who are asking these sorts of questions, and we don't know how to answer them. Can you help?