systemd-networkd 使用 HE IPv6 Tunnel

创建文件：/etc/systemd/network/he-ipv6.netdev

[NetDev]
Name=he-ipv6
Kind=sit

[Tunnel]
# IPv6 Tunnel Endpoints|Server IPv4 Address
Remote=66.220.18.42
# Local IPv4 | NAT-Address
Local=204.194.52.86
TTL=255

创建文件：/etc/systemd/network/he-ip.network

[Match]
Name=he-ipv6

[Network]
# IPv6 Tunnel Endpoints|Client IPv6 Address>/64
Address=2001:470:c:1271::2/64
# IPv6 Tunnel Endpoints|Server IPv6 Address
Gateway=2001:470:c:1271::1
DNS=2001:470:20::2

[Route]
# IPv6 Tunnel Endpoints|Server IPv6 Address
Gateway=2001:470:c:1271::1
Destination=::/0

[RoutingPolicyRule]
# IPv6 Tunnel Endpoints|Client IPv6 Address>/64
From=2001:470:c:1271::2/64

[RoutingPolicyRule]
# Routed IPv6 Prefixes|Routed 64>/64 - OR - Routed IPv6 Prefixes|Routed 48>/48
From=2001:470:d:126e::/64

来源：IPv6 tunnel broker setup – Arch Wiki, Systemd-networkd tunnel setup – Hurricane Electric’s IPv6 Tunnel Broker Forums