BT man should be coming this afternoon. Due to serious illness I would be ready at my end, so the plugging in of the small switch and plugging in of all modems will have to be done later in the week. I have done the small switch config ready, also the Firebrick config with vlans is written, ready, but untested. I can't remember where I have got to with programming a modem ready to fulfill its role as modem #4 listening to admin i/f on 192.168.4.1. I have finished testing the tool that I have put together to customise XML config files for modems to set them to be modem #n, so I can just use that on a suitable modem.