I used two of Spirent Communications’ SmartBits 6000 chassis to load up half of our 3750 stack with roughly 50 percent 100Mbps ports and 50 percent Gigabit ports. I then blasted 100 percent port utilization 64-byte, 512-byte, and 1,518-byte frames. The 3750 Stack didn't drop a frame, and I even ran a protected video stream (from a DVD-equipped server to a client on the other side of the network) through the stack simultaneously without degradation. Finally, I used my SmartBits to test latency at multiple packet sizes during full port utilization. The 3750 handled this with aplomb, allowing only 24 microseconds at 64 bytes, 37 microseconds at 512 bytes and 52 microseconds at 1,518 bytes.
I also tested the 3750’s high claims of redundancy. First, after configuring my three 3750s into a stack, I disconnected one switch while running a basic traffic blast via our SmartBits and a DVD movie from my test server to my test client. I noticed a momentary blip in the play of the movie at the time of disconnection, but the system picked up in less than a second, and no more degradation was visible.
I performed the same procedure in the next test, though I made sure to disconnect the stack’s master switch this time. Not only did switching continue uninterrupted, I was still able to manage the stack via IOS and CMS as a single-address cluster.