auto vlan switch port configuration

I recently set up a switch (Linksys managed switch - horrible horrible
management interface!!!) and am sure I saw something in there about a
protocol for the device plugged into that port to automatically
configure the switch end of the port wrt vlan trunking and tagging...

Does such a protocol exist, or did I just imagine it? If so, is it
supported by the Linux vlan implementation?

Thanks

James