Hi, I have a IPv6 tunnel terminating on a Cisco router with a statick publick IPv4 addres My config (as done folowing the website's instructios) interface Tunnel10 description IPv6 uplink to SixXS no ip address ipv6 address xxxx:xxx:xxx:xx::2/64 ipv6 enable ipv6 mtu 1280 tunnel source xx.xx.xx.xx #my static IPv4 tunnel destination 213.219.173.138 tunnel mode ipv6ip interface FastEthernet0/0 description LAN ip address 192.168.13.254 255.255.255.0 no ip redirects no ip unreachables no ip proxy-arp ip nat inside ip virtual-reassembly ip route-cache flow speed 100 full-duplex ipv6 address xxxx:xxx:xxx:xxxx::/64 #subnet range ipv6 enable ipv6 nd ra-interval 60 ipv6 nd ra-lifetime 180 ipv6 nd prefix xxxx:xxx:xxx:xxxx::/64 #subnet range no mop enabled whene I enable IPv6 on the nic of my client pc (Ubuntu 11.10) I do get an IP address and can do PING6 and traceroute6's ALso surfing to IPv6 websites or duals stacked ones is no problem. However, when I try to visit a website (Firefox 11) that is only IPv4 I can not reatch it, unless I add .sixxs.org to the url... Is this normal? I thought the brouser was supposed to try IPv6 first and then downgrade to IPv4 whene IPv6 is not avaialble... I can figure out to add the sixxs.org when thinks do not work, but: -my wife and kids are not that technical so a more "simple sollutio" should be nice -https site (netbanking) do not recognise the .sexxs.org and won't load becouse sertifacat is not correct... KInd ragards Jobj