Opera Browser problem

[Ted Mittelstaedt]

This came up on the SpamAssassin mailing list,
I just thought people might be interested:

Tore Anderson wrote:
> Hello list,
> 
> I've been doing some testing in order to determine whether or not it
> would be «dangerous» for our customers to dualstack their web sites. The
> largest problem I've found so far affects a very specific group of
> clients, which:
> 
> 1) are using Windows Vista or newer, and
> 2) are using the Opera web browser, and
> 3) are assigned public IPv4 addresses, and
> 4) are on a network which filters inbound proto-41 traffic.
> 
> In this case, the client will have a 6to4 tunnel interface automatically
> configured, and will prefer using it over native IPv4 for contacting
> dualstacked web sites.  

Further discussion on the SA list about this indicates this is
a known bug that was reported to Opera - but the broken browsers
are out there, of course.

Ted