Hi folks,

Follow the Setup of 6to4 tunnel guide, I want to test ipv6 connectivity, but I cannot ping6 to ipv6.google.com.

Details below:

# traceroute 192.88.99.1
traceroute to 192.88.99.1 (192.88.99.1), 30 hops max, 40 byte packets
 1  static.vdc.vn (123.30.53.1)  1.514 ms  2.622 ms  3.760 ms
 2  static.vdc.vn (123.30.63.117)  0.608 ms  0.696 ms  0.735 ms
 3  static.vdc.vn (123.30.63.101)  0.474 ms  0.477 ms  0.506 ms
 4  203.162.231.214 (203.162.231.214)  11.327 ms  11.320 ms  11.312 ms
 5  static.vdc.vn (222.255.165.34)  11.546 ms  11.684 ms  11.768 ms
 6  203.162.217.26 (203.162.217.26)  42.460 ms  42.424 ms  42.401 ms
 7  218.188.104.173 (218.188.104.173)  42.489 ms  42.462 ms  42.415 ms
 8  218.189.5.10 (218.189.5.10)  42.613 ms 218.189.5.42 (218.189.5.42)  42.273 ms  42.300 ms
 9  d1-26-224-143-118-on-nets.com (118.143.224.26)  205.752 ms d1-18-224-143-118-on-nets.com (118.143.224.18)  207.130 ms d1-14-224-143-118-on-nets.com (118.143.224.14)  206.970 ms
10  218.189.5.150 (218.189.5.150)  207.456 ms  206.349 ms  206.941 ms
11  * * *
12  10gigabitethernet2-1.core1.lax1.he.net (72.52.92.121)  214.087 ms  214.426 ms  214.818 ms
13  192.88.99.1 (192.88.99.1)  207.215 ms  199.270 ms  209.391 ms

# ifconfig tun6to4
tun6to4   Link encap:IPv6-in-IPv4  
          inet6 addr: 2002:x:x::/16 Scope:Global
          inet6 addr: ::x.x.x.x/128 Scope:Compat
          UP RUNNING NOARP  MTU:1480  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:11 dropped:0 overruns:0 carrier:11
          collisions:0 txqueuelen:0 
          RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b)

# iptunnel 
sit0: ipv6/ip  remote any  local any  ttl 64  nopmtudisc
tun6to4: ipv6/ip  remote any  local x.x.x.x  ttl 64 

# ip -6 route show
::/96 via :: dev tun6to4  metric 256  expires 21332777sec mtu 1480 advmss 1420 hoplimit 4294967295
2002::/16 dev tun6to4  metric 256  expires 21332794sec mtu 1480 advmss 1420 hoplimit 4294967295
fe80::/64 dev eth0  metric 256  expires 15674592sec mtu 1500 advmss 1440 hoplimit 4294967295
fe80::/64 dev eth1  metric 256  expires 15674597sec mtu 1500 advmss 1440 hoplimit 4294967295
fe80::/64 dev tun6to4  metric 256  expires 21332794sec mtu 1480 advmss 1420 hoplimit 4294967295
default via ::192.88.99.1 dev tun6to4  metric 1  expires 21332861sec mtu 1480 advmss 1420 hoplimit 4294967295

# ping6 -n -c 4 ipv6.google.com
PING ipv6.google.com(2404:6800:8005::68) 56 data bytes
From 2002:x:x:: icmp_seq=0 Destination unreachable: Address unreachable
From 2002:x:x:: icmp_seq=1 Destination unreachable: Address unreachable
From 2002:x:x:: icmp_seq=2 Destination unreachable: Address unreachable
From 2002:x:x:: icmp_seq=3 Destination unreachable: Address unreachable

--- ipv6.google.com ping statistics ---
4 packets transmitted, 0 received, +4 errors, 100% packet loss, time 2999ms

What is my problem?

Thanks,