I just recently got a fiber line installed into my office, and with the exception of an odd bit of trouble that we're having, things are working good, and the network response is really amazing.
The problem that we're having is that every once in a while, my router will flake out and drop packets. It's not the line, and it's not the switch. It's the router itself, and I've switched out the hardware, and both pieces do it. The piece of equipment that I'm using is a Juniper Netscreen SSG5. Here are the symptoms:
I do a pingflood to the "internal" interface, with
ping -f -c 10000 <internal-ip>
and I get 10,000 responses. Every time. Then, I'll do the same thing, except to the IP address of the external interface (but still on the same device). It drops somewhere between 10 and 15 packets out of 10,000. I've done the same test on every other gateway in the company, and nothing else shows this behavior. I'm perplexed.
I've talked with the support from the fiber company, and both of our interfaces are hard-coded to 100Mb with full duplex, if that could even cause the problem. Incidentally, when pinging the exterior interface from inside the router, I never lose a packet, which makes me think that it isn't the interface itself. And the local interface never loses a packet, so it isn't the switch.
I'm honestly not sure where the problem could lie, except with the design of the hardware itself. I've watched the graphs, and even during the pingflood, I'm nowhere near maximizing the CPU or memory on the router.
For Tom: The fiber is 13Mb/s, but when I ping the interface, it isn't crossing over to the fiber. The local LAN is running at 100Mb/s, and the internal interface responds to every packet. I'll have to see if I can borrow another piece of hardware, but I've got some older model Junipers (5GTs) at different sites that don't show the same symptoms.