Well, that's a question with a lot of possible answers. Here is a couple of things you could check. - A basic switch should not interfere with the drive unit talking to the router, but you have proved that somehow it does. So we will concentrate on that for now.
Your router should be the only DHCP server dishing out addresses to all your LAN devices, even if they are behind the switch. The switch, (unless its something a bit more complex) normally does not assign IP addresses. A basic switch's job is make sure that busy devices on one port don't bog down all the other devices on other ports and, of course, to give you more places to plug things into.
Based on that, here are some thoughts.
- Extremely unlikely, but could your switch actually be another router and not a switch? This would actually create yet another network segment and the SC101 stuff I read on their web page says that it will not easily work on a separate segment. Not likely the case. They may look similar but routers usually require more initial setup than a switch. Most switches are auto-sensing, plug and play jobies these days.
- Again a simple question, but have you tried different ports on the switch. Two reasons.
First is that it is not uncommon for a single port on a switch to go bad and just stop working. Sometimes this can be resolved, other times they just physically die.
Secondly, it may have one port (usually the first or last) that can be set up as the 'Uplink' port. That's the port that would normally connect up towards your router. Some switches do not allow you to use an uplink port as a regular port without making some config changes.
- Is your switch 'auto-sensing'? More complex or older switches required you to manually config each port for use. This is not likely a concern as all but really old consumer switches are usually fully automatic in this sense.
-- Sometimes the data tables in a switch get fouled up, specifically something called an ARP table. You may be able to go in and clear this table so it will rebuild itself from scratch. However, I bet you have already done this in a more simple manner by powering the switch down and turning it on again.
-- I read on the Netgear web sight that the SC101 is very sensitive to having all the important network devices turned on in a very specific pattern. Here is the link to the troubleshooting page where I read this.
NetGear SC101 TS Guide I find it odd that it says you MUST turn on the SC101 before turning on the modem and router. Normally.....You want the DHCP server (the router in this case) to be turned on first. That is because most client devices like to send out the DHCP request (Hey! Can anyone out there give me an IP address?????) as soon the device is turned on. Many, only try once and then give up.
Obviously this one keeps repeating its request until it gets one. But why should it be turned on first? This part scares me a bit but then again, home-consumer devices are not my speciality so this could be more normal than I think.
It is very specific in it's instructions on the way to power things up though, so it might be something to try.
-- Documentation also says it doesn't talk well through a router (two different networks). All of your devices are on the same side of the router so the switch shouldn't make a difference in this manner. It still should all be the same network. It does make me wonder if maybe the switch is trying to do something a bit more fancy with the different physical segments it creates.
If you give me the make and model, we might be able to at least rule that out.
I have some other ideas but they would take longer to explain and I'm all out of my sandwich and chocolate milk so I'll let you make some confirmations on those things then maybe we can narrow it down further.
I also saw mixed up in the Netgear help files a way to connect to the storage device and confirm if and what IP it actually received. It's a command line interface so it's not user friendly. I wouldn't play around with it there unless you are fairly confident with the steps it lays out.
Hopefully this helps get you started. Sometimes these networked storage devices can be very cantankerous. You might find it's just easier to keep it plugged in directly to the router.
