IPv6 support on Virgin media

Just a quick comment about 6to4.  It was/is a really useful tranition mechanism.  As already pointed out a native IPv6 connection is preferable whether possible. 

However there is one major limition.  Because the tunnels are brittle, with no guarantee of latency or bandwidth, its generally considered to be less reliable than IPv4.  Because of this the newer IPv6 compatible Operating Systems, with the exception of Mac OSx, will prefer a native IPv4 connection to a 6to4 connection.  When connecting to an IPv6 only host, such as ipv6.google.com, this does not matter, as there is no IPv4 to fall back on.  However a pure dual stack domain, such as heise.de, will result in a IPv4 connection. 

Those with an interest in IPv6 may have heard about Googles whitelisting system.  Unless your DNS servers are registered with Google, they will not serve you quad AAAA records (the IPv6 address records) for their domains (apart from the afore mention IPv6 specfic ones).  The reason for this is 'brokeness' that they have observed for users who connect over IPv6.  The majority of this brokeness appears to be due to 6to4. 

So play with 6to4, but be aware of some of the limitations, and make a fuss demanding IPv6.   Another telco in France, deployed 6rd, a tunnelled version of IPv6, and made it available to all their customers within 5 weeks.  They had a advantage with the managed kit they provide to their subscribers, but you have to ask why Virgin are not able to do something similar, especially when you consider many of the routers they provide can be flash with open-wrt, and Comcast in the US's 6rd trial is using a modifed open-wrt for their 6rd.