For Wanadoo subscribers that discover that news.wanadoo.fr doesn't work…
The French ISP “Wanadoo” offers a Usenet news server, like all ISPs. Its name is news.wanadoo.fr… except that it isn't.
When you ask any DNS server to resolve the name news.wanadoo.fr, you get (at the moment) 220.127.116.11 as IP address. (In fact, news.wanadoo.fr is an alias for feed-news.wanadooportails.com, which resolves to that number). But that machine doesn't respond to the NNTP protocol.
What is going on is that the DNS server that Wanadoo offers to its ADSL subscribers resolves the name differently from other DNS servers in the world. The number it gives is 18.104.22.168 (corresponding to news-reader.wanadooportails.com). And that machine does respond to NNTP.
Very confusing if you use a different DNS server, which may happen, e.g., if you are using Linux or have a local network.
In fact, if you ask what the IP number is of the DNS server that Wanadoo recommends to its subscribers (ns.wanadoo.fr), it turns out that it, too, has a different address depending on who you ask: 22.214.171.124 according to the rest of the world, 126.96.36.199 according to Wanadoo.
Wanadoo relies on it that you use the DNS servers that it passes on when you connect to ADSL (i.e., 188.8.131.52 and 184.108.40.206), either all the time, or at least once to resolve ns.wanadoo.fr. If you never use either of those, but use ns.wanadoo.fr directly, or use a completely different DNS server, you'll never get to Wanadoo's NNTP server either.Bert Bos