I have a managed switch that handles the vlan config. VoIP phones run on one, everything else on another. I need to buy some off the shelf switches due to the difficulty of adding another drop in some locations of our office. How can I tell if an off the shelf dumb switch will work with the vlan setup?
SnapOverflow
dumb switch == no vlan support. You need a managed switch. Now that being said, if all the machines that will be plugged into the switch will be on the same vlan, you don't need vlan support in the switch as it will be untagged traffic anyway. If you need to do fancier stuff like voice vlans, trunks, or multiple vlans you need a managed switch.
Do your VoIP phones have integrated switches? If so it's quite possible you can send a trunk to the phone and have the phone use one VLAN while the port on the switch is another VLAN.
For other small/cheap switches, any sort of VLAN support is unlikely. If it doesn't have a serial port on the front, you likely won't be able to do any management. If it does, you can likely search on the model number and find documentation online detailing feature support.
All that said, what is the layout being supported? If you're looking to put two devices in individual offices with one port each, you're going to have a hard time finding anything. Some managed switches can handle multiple "untagged" VLANs per port and split based on 802.1x/MAC authentication, but if you're having to ask having the setup to support that is unlikely. At least one manufacturer made wall jacks integrating a PoE-powered switch with VLAN support several years ago, but I haven't heard of that becoming common (or even around anymore). Splitting cables is possible but discouraged with pre-gigabit and no PoE, but that'd be last resort and I'd guess the phones may need PoE anyways.
If you have a shared workspace with only a few drops that need more, you could have one drop be VoIP, one be general computers, etc. Then attach a dumb switch to each drop and cable only that type of device to it.
So after some trial and error I have discovered that off the shelf switches manufactured in the last few years will handle this traffic correctly. There is a bit of guesswork required though, because none of them seem to give any information one way or the other.