我已经设置了从家到远程主机的无编号 L2tp 隧道。在尝试 ping ipv6.google.com 时，我收到了超出范围的错误，我知道以前不应该以这种方式使用本地链接地址，但现在有了无编号接口，这应该是可能的。
两台机器都运行最新的 Debian Jessie，但内核较新4.6.0-0.bpo.1-amd64
隧道：
~> sudo ip l2tp show tunnel
Tunnel 386, encap IP
From 192.168.88.254 to remote_host
Peer tunnel 381
地址和路线：
首页 ~> ip -6 地址
5: l2tpeth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1492 state UNKNOWN qlen 1000
inet6 fe80::8427:7dff:fea4:939b/64 scope link
valid_lft forever preferred_lft forever
~> ip -6 route
local ::1 dev lo proto kernel metric 256
fe80::/64 dev vnet0 proto kernel metric 256
fe80::/64 dev l2tpeth0 proto kernel metric 1024
default via fe80::f94e:693a:aa66:e79b dev l2tpeth0 metric 1024
远程主机 ~> ip -6 地址
5: l2tpeth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1460 state UNKNOWN qlen 1000
inet6 fe80::f94e:693a:aa66:e79b/128 scope link
valid_lft forever preferred_lft forever
inet6 fe80::f434:73ff:fef3:5236/64 scope link
valid_lft forever preferred_lft forever
~> ip -6 route
local ::1 dev lo proto kernel metric 256
2400:8900::/64 dev eth0 proto kernel metric 256 expires 2591997sec mtu 1300
fe80::f94e:693a:aa66:e79b dev l2tpeth0 proto kernel metric 256
fe80::/64 dev eth0 proto kernel metric 256 mtu 1300
fe80::/64 dev tun0 proto kernel metric 256
fe80::/64 dev l2tpeth0 proto kernel metric 256 mtu 1460
default via fe80::1 dev eth0 proto ra metric 1024 expires 87sec mtu 1500 hoplimit 64
平安：
~> ping6 fe80::f94e:693a:aa66:e79b%l2tpeth0
PING fe80::f94e:693a:aa66:e79b%l2tpeth0(fe80::f94e:693a:aa66:e79b) 56 data bytes
64 bytes from fe80::f94e:693a:aa66:e79b: icmp_seq=1 ttl=64 time=61.9 ms
64 bytes from fe80::f94e:693a:aa66:e79b: icmp_seq=2 ttl=64 time=58.4 ms
64 bytes from fe80::f94e:693a:aa66:e79b: icmp_seq=3 ttl=64 time=57.4 ms
64 bytes from fe80::f94e:693a:aa66:e79b: icmp_seq=4 ttl=64 time=56.5 ms
64 bytes from fe80::f94e:693a:aa66:e79b: icmp_seq=5 ttl=64 time=66.1 ms
^C
--- fe80::f94e:693a:aa66:e79b%l2tpeth0 ping statistics ---
5 packets transmitted, 5 received, 0% packet loss, time 4006ms
rtt min/avg/max/mdev = 56.509/60.113/66.190/3.562 ms
在家里 ping Google：
ping6 ipv6.google.com
PING ipv6.google.com(hkg12s01-in-x0e.1e100.net) 56 data bytes
From hkg12s01-in-x0e.1e100.net icmp_seq=1 Destination unreachable: Beyond scope of source address
From hkg12s01-in-x0e.1e100.net icmp_seq=2 Destination unreachable: Beyond scope of source address
^C
--- ipv6.google.com ping statistics ---
2 packets transmitted, 0 received, +2 errors, 100% packet loss, time 1001ms
远程 tcpdump：
~> sudo tcpdump -ni l2tpeth0 icmp6
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on l2tpeth0, link-type EN10MB (Ethernet), capture size 262144 bytes
09:34:19.944576 IP6 fe80::8427:7dff:fea4:939b > 2404:6800:4005:801::200e: ICMP6, echo request, seq 1, length 64
09:34:19.944749 IP6 fe80::f94e:693a:aa66:e79b > fe80::8427:7dff:fea4:939b: ICMP6, destination unreachable, beyond scope 2404:6800:4005:801::200e, source address fe80::8427:7dff:fea4:939b, length 112
09:34:20.946277 IP6 fe80::8427:7dff:fea4:939b > 2404:6800:4005:801::200e: ICMP6, echo request, seq 2, length 64
09:34:20.946397 IP6 fe80::f94e:693a:aa66:e79b > fe80::8427:7dff:fea4:939b: ICMP6, destination unreachable, beyond scope 2404:6800:4005:801::200e, source address fe80::8427:7dff:fea4:939b, length 112
^C
4 packets captured
4 packets received by filter
0 packets dropped by kernel
远程主机上的 sysctl（ipv6 转发已开启）：
net.ipv6.conf.all.forwarding = 1
net.ipv6.conf.default.forwarding = 1
net.ipv6.conf.eth0.forwarding = 1
net.ipv6.conf.l2tpeth0.forwarding = 1
答案1
Beyond scope of source address意味着您没有足够大范围的 IPv6 地址来到达目的地。
具体来说，你只有一个链接本地地址，因此你可以仅有的到达该第 2 层链路上的 IPv6 地址。在这种情况下，这意味着您只能到达隧道的另一端。
为了访问互联网，您需要全球范围的 IPv6 地址，并且需要它们路由到您（和从您路由）。您可以从互联网服务提供商、大学、数据中心等处获取这些地址。