I have a network with two N7 (2 x 7G4280-19 blades) in the core and several stacks with secureStacks B and C in the access. Almost all access stacks are connected to the two core boxes (N7). The two core N7 are interconnected with two 10G links in lag.
Multiple servers and other devices are connected to a C3 switch. This switch (C3) also has a uplink for each Core N7. A second C3 also has a uplink for each core N7. In this second C3 are connected the redundant links of the servers.
In a random way I'm having all the networks "down" because the route bridge gets with the "switch Packet Processing more than 60%.