even though I've been involved with them since I worked at the University of Toronto Computer Research Facility in the early 1970s while attending that institution.
Artisan Radio runs an FTP server to distribute programs that we've created, mostly Teenage Dreams.
This morning, I went to transfer a few programs into the distribution directory, and could not connect. This, despite not having touched the server software, never mind IIS (which contains FTP) in months. I've so far determined that it isn't the FTP client software (the same error occurs in multiple clients) and it happens with other users at other sites. Rebooting the router and server did nothing. So it's either cosmic rays generating random quantum effects or something else surrounding the site has changed - something that I don't explicitly control. Our IP address is one possibility, and I'm sure I will come up with others once I get away from the problem for a while and really think.
It's difficult enough to run a computer site with outside users without these kinds of issues popping up. I have enough problems scheduling time to record the radio programs. This week, I barely made the deadline for our 50th Teenage Dreams Special.
Well, I was right. It was my IP that changed. And you may well ask, what might that have to do with the particular problem I described, as it's not obvious.
Well, it turns out that if you're running an FTP server, and you use passive connections (which are by far the most common and the most secure), IIS (and probably any FTP server) needs the server firewall external (Internet) IP address.
My ISP provides dynamic IP addresses, and I use a service called no-ip to map that dynamic ip address to the site artisanradio.hopto.org. They give you software to run on your computer to update their mappings when the IP changes. You can also use artisanradio.com to access my site, as I redirect all requests within my ISP to artisanradio.hopto.org. Using a static IP address would be preferable, but most ISP's will not give those out unless you use a much more costly business plan - and then you pay for that static IP on top of that.
So that dynamic IP for the station must have changed at some point between the last time FTP was used and now (during the last few weeks). The station kept trundling along, but FTP was silently disabled until I updated that IP address internally within IIS. I'll have to do some research to see if I can write some script or software to automatically update it; until I can (if I can) I'll just have to manually check to see if the IP address is correct when FTP is going to be used. It's not like there are dozens of stations lining up to get Teenage Dreams (right now, there's only one, but it is freely available to any Part 15 station, all you have to do is ask).