Second hand routers often have the previous user's details still held within, and require a reset before use, so I would think, probably, yes, David, although, of course, the IP address is determined by the ISP, and the router just uses whatever it is, as I understand it. If it came to it, the worst that would be required would be to reset it and start again, which, as you know, isn't a terribly difficult task. If it's just a question of swapping one for another, there shouldn't be any problem reconnecting the old one, if necessary.