We are implementing 4710's in our core network..
--what could be the best design structure from a simplicity point
Design would vary based on specific requirements. To connect it to a specific layer on the network (core/agg) you would have to check the traffic flow to decide what suits you best.
In terms of ACE design, if source IP visibility is not a requirement, One-arm mode with Source NAT provides the ability for non load balanced traffic to bypass the ACE. If it is a requirement you can use PBRs but that complicates things a little because you have to now manage the routers for changes on the ACE. With routed mode, the design is simple and servers point to the ACE as their default gateway. Need to weigh the pros and cons of each of the options based on the specific requirements.
--one interface vlan for for vips---connected front end to the core..and backend for servers (routed mode)
Yes - for routed mode that would be the way to do it. In this case, in addition to load balancing, the ACE routes non-loadbalanced traffic to/from the servers.
should you have more than one interface vlan for servers and or clients?
- Depends in your subnets. If you have separate subnets for your web/app/db servers then it is a good idea to have different subnets. Also, you may want to think about separate contexts if you want complete isolation between the layers.
--at which point would u need multi context.......besides an Admin context
As far as possible, try to keep the Admin context only for administration. Make a separate context(s) for load balancing and manage the resources to it.
--should you put a management interface on each context?
Yes - that would give you the ability to have different users manage only their contexts.
Hope that helps .
