In reaction to comments on his entry The Other Way, Matt Palmer wrote in part about my concerns about office switch uplink bandwidth for sysadmin drops (in WiringForSysadminsII):

[...] What I question is the need for constant, sustained gigabit over an extended period to another isolated machine such that you need a dedicated link to them.

I sort of half-agree that sysadmin machines and drops don't need constant, sustained gigabit bandwidth (although I'm not entirely sure about that). But what they do need is occasional periods of real gigabit bandwidth, and real gigabit bandwidth when you can be absolutely sure that the underlying link will deliver gigabit data rates and the only performance limits are those created by the machines, switches, and so on at either end.

If I'm testing how fast hardware and software can go or if I'm trying to investigate network performance problems that have been reported to us, I need an environment that is not artificially contaminated by other networking traffic coming in to my heavily VLAN'd office switch. I know that some amount of contamination is there (I have tcpdumps of our internal networks and some of them are remarkably noisy); it may be enough to be significant, or it may not be. I don't want to have to guess about it and make assumptions. I want a clean gigabit, one that's as close as possible to what machines and users would see in the real environment in our machine rooms or in user offices.