跟着6to4 隧道设置指南，我想测试 ipv6 连接，但我无法 ping 到 ipv6.google.com。
详情如下：
# 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
我的问题是什么？
谢谢，
答案1
6to4 机制非常脆弱，目前不推荐使用。
由于您没有选择出口中继，因此如果中继失效或配置错误，您无法更改它。这可能是您的问题（中继在 v4 中可访问，但您无法确定主机上的 6to4 机制是否已启动），但您无法使用另一个出口节点来检查...
如果 6to4 中继路径上的防火墙正在过滤协议 41，则还存在另一种失败的可能性。在这种情况下，您也无法设置 6in4 隧道。
答案2
抱歉，我的“打字错误”。我的公共 IPv4 是：xxx127，但我输入的是：
ip tunnel add tun6to4 mode sit ttl 64 remote any local x.x.x.27
现在，我可以 ping6 并 traceroute6 到 ipv6.google.com：
# ping6 -n -c 4 ipv6.google.com
PING ipv6.google.com(2404:6800:8005::63) 56 data bytes
64 bytes from 2404:6800:8005::63: icmp_seq=0 ttl=58 time=217 ms
64 bytes from 2404:6800:8005::63: icmp_seq=1 ttl=58 time=217 ms
64 bytes from 2404:6800:8005::63: icmp_seq=2 ttl=58 time=217 ms
64 bytes from 2404:6800:8005::63: icmp_seq=3 ttl=58 time=217 ms
--- ipv6.google.com ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3001ms
rtt min/avg/max/mdev = 217.258/217.366/217.489/0.577 ms, pipe 2
# traceroute6 ipv6.google.com
traceroute to ipv6.google.com (2404:6800:8005::63), 30 hops max, 40 byte packets
1 2002:c058:6301::1 (2002:c058:6301::1) 199.193 ms 199.169 ms 199.153 ms
2 gige-g4-12.core1.lax1.he.net (2001:470:0:14e::1) 199.279 ms 199.268 ms 199.403 ms
3 PR01.LAX03.google.com (2001:504:0:3:0:1:5169:1) 199.633 ms 199.620 ms 199.755 ms
4 2001:4860::1:0:991 (2001:4860::1:0:991) 242.128 ms 2001:4860::1:0:607 (2001:4860::1:0:607) 204.765 ms 2001:4860::1:0:991 (2001:4860::1:0:991) 204.753 ms
5 2001:4860::1:0:7ea (2001:4860::1:0:7ea) 235.740 ms 243.709 ms 2001:4860::1:0:21 (2001:4860::1:0:21) 233.959 ms
6 2001:4860::1:0:75 (2001:4860::1:0:75) 215.427 ms 233.980 ms 2001:4860::1:0:47 (2001:4860::1:0:47) 214.836 ms
7 2001:4860::1:0:1063 (2001:4860::1:0:1063) 242.264 ms 2001:4860::1:0:16 (2001:4860::1:0:16) 216.691 ms 2001:4860::1:0:1063 (2001:4860::1:0:1063) 242.287 ms
8 2001:4860::2:0:119c (2001:4860::2:0:119c) 217.665 ms 2001:4860::2:0:119b (2001:4860::2:0:119b) 217.597 ms 217.436 ms
9 * 2001:4860:0:1::e1 (2001:4860:0:1::e1) 221.650 ms *
10 2404:6800:8005::63 (2404:6800:8005::63) 216.882 ms 216.917 ms 216.897 ms
我将尝试配置 6in4 隧道，看看它与 6to4 隧道有何不同。
感谢您的信息。