I tried the suggested URL as in bobble_bob's post and got a page of what looked like java script. After running the second URL I then got an error message from Firefox saying could not connect, so it worked for me.
The downside now is that I can't connect to the router admin interface so I'll have to leave it a few days and wait to see an announcement that an update is available so I can reboot and download it. I checked an hour or so ago and no update was shown as available then.
p.s. - further downside is that I've ended up on a gateway (+Net psb-bng04) where I am getting a lot of dropped packets while I'm trying to watch Ronnie O'Sullivan perform. I night even have to go and switch the TV on!!
Edited by longedge (Wed 14-Dec-16 20:06:39)