Simple Question about Traffic Flow - Simple Answer Required
Ok, quick question. Its been about 5yrs since I worked on load balancers. I've done Cisco CSS, ACE and NetScaler before it was acquired by Citrix in the past. I'm just trying to verify something in my mind. When you do a simple VIP with real servers behind it with L4 Port load balancing; does the traffic go through/get pinned through the load balancer. I'm not talking about a url redirect off box. I'm talking about servers that are behind the balancer.
Only reason I'm asking is. Think about a VIP in the DMZ (say port 80 for a super simple example), the servers themselves aren't directly exposed to the internet. Only the VIP is NAT'ed so server traffic would have to flow back through the balancer, to return to the client. But on the LAN someone is trying to convince me that no.. if the VIP is on the same subnet as the real servers, the VIP balances it off to lets say one of 2 servers and the client talks directly to it.. that make no sense to me. Especially thinking about methods of persistence. What would facilitate that if the balancer said here's your server now leave me out it...
I'm only asking because I am a long time networking dude and in one case that I know of a Cisco voice gateway can do that, with a feature called "Media Flow Around" but thats in the case of the voice packets. The gateway says to the phone here is your other phone now move me out of the path of the direct flow of the conversation. But in my mind thats a special case.
Can someone please confirm, and PLEASE don't send me a link to some gigantic F5 flow chart.
Thanks everyone!