Here is a little design problem for you guys. On the attached diagram, all network fiber terminates in the center cabinet (B). Servers and router are located in cabinet A. I want to design this with no single point of failure that would affect the entire LAN. Of course, if an edge switch goes out it will affect users connected to that switch, but the rest of the LAN will continue to function.
The concept on the attached diagram is that there are 2 EI 3560's in cabinet A running HSRP. Each of these is connected via fiber to each outlying cabinet. This means that 4 strands of fiber are used for each cabinet, and I only have 12 strands available between A and B. Of course, the simplest solution to this problem is to pull some more fiber between A and B. Another solution might be to carry 4 CWDM wavelengths over a fiber pair between A and B. I can think of a few others.
Anyone care to contribute an idea? Costs, of course, must be kept to a minimum.