TCP redirect on LB_FAILED for in-band health check.

 

I've found that LB::status is great if you want to know ltm's current understanding of a member's status. However, I don't think the status is instant. I remember having to handle a situation where LB::status would report "up" even though a node had just failed. If you handle the LB_FAILED event, you can know instantly that a member has just failed. I think that LB::status would report "up" until a health check or irule marked the member as down.

 

 

So basically, LB::status helps let you know ltm's current (which can be delayed by health check interval) knowledge of a member. I found that handling LB_FAILED is more "instant".