Can you clarify your setup? Your IPv6 tunnel is part of which network? Based on your line above it should be SIXXS-NLAMS05. So I don't see why there should be a problem if Scarlet is allowing IPv6 NNTP clients from their IPv6 cloud. But your routing might be an issue if you also have a XS4ALL IPv6 tunnel. PS: There is little to hide if you give away the network part. The other part is a given value for both ends of the tunnel.

I have an AYIYA IPv6 connection through a Scarlet POP. I cannot access that Scarlet server either, so I guess that the Scarlet ipv6 news server is no longer offered to public access. Pinging dreaderd-2.news.ipv6.scarlet-internet.nl [2001:960:3:119::2] from 2001:960:2:531::2 with 32 bytes of data: Request timed out. Request timed out. Request timed out. Request timed out. Ping statistics for 2001:960:3:119::2: Packets: Sent = 4, Received = 0, Lost = 4 (100% loss), Pinging newszilla6.xs4all.nl [2001:888::119] from 2001:960:2:531::2 with 32 bytes of data: Reply from 2001:888::119: time=15ms Reply from 2001:888::119: time=15ms Reply from 2001:888::119: time=14ms Reply from 2001:888::119: time=13ms Ping statistics for 2001:888::119: Packets: Sent = 4, Received = 4, Lost = 0 (0% loss), Approximate round trip times in milli-seconds: Minimum = 13ms, Maximum = 15ms, Average = 14ms tracert news.ipv6.scarlet-internet.nl gives me rows of three stars after two hops.