Front End NLB

[Elway7]

I have a network load balanced front end design.
I have two front end servers and one back end.
The problem i having is that when users hit OWA using the nlb name it is fine but if one server goes down then OWA crashes as well and they have to wait up to 15 minutes before they can get in.
If i do a ping test and unplug each nlb one at a time it fails over fine. Not sure if there is something i have done wrong or if this somehow is the design of nlb. I know nlb is not like clustering but i wanted some type of fault tolerance.

Thanks

 

[ShackDaddy]

If one server goes down, no one can connect for 15 minutes, or just people that were connected to the server that went off-line? If you were connected to the server that failed, and you closed your web browser and then opened a new browser and attempted to connect, you should be able to connect to the existing system.

I don't think this is an Exchange-specific problem, I think it's related to the NLB subsystem. When one of the members of the cluster drops out, what do you see when you do a 'wlbs query' from the command-line on one of the nodes? It should show you the status of the cluster and the current membership. You should also be able to test taking one of the nodes offline using the 'wlbs stop' command on one of the nodes to see how the status of the NLB cluster is changed.

ShackDaddy
Shackelford Consulting

 

[Elway7]

i think u are correct in saying it must be an nlb issue, but i have no idea where i went wrong.
If the primary node gets disconnected things are ok, but if my secondary niode gets disconnected then my owa page does not work and i need to re-boot both of my fe servers.
Any thoughts

 

[ShackDaddy]

NLB doesn't really use primary and secondary nodes, to my understanding. They are usually equal in status and share a virtual IP address.

Can you connect to each one individually by its individual name and use OWA? And when you connect to the clustered name/IP, you've set it up to default to the primary node? How have you set it up to create a primary and secondary? I'm more familiar with NLB in the web-server context, not the OWA/FE context, so I may be missing something. How did you set up affinity?

ShackDaddy
Shackelford Consulting