Wireguard & OpenWRT

Goal: setup my Android handset so that it can connect remotely to hosts on my home network

Follow the OpenWRT Wiki guide for general Wireguard setup.

Addressing

My handset typically doesn’t have IPv6 Internet connectivity, so Wireguard traffic will be over IPv4. However traffic inside the tunnel can be over IPv6.

Wireguard

Android Wireguard config:

[Interface]
Address = fd2c:cfce:c1ce:10::2/64
DNS = fd2c:cfce:c1ce:10::1
PrivateKey = xxxxxxxxxxxxxxxxxxxxxx

[Peer]
#AllowedIPs = fd2c:cfce:c1ce::/48
AllowedIPs = ::/0
Endpoint = 203.123.xx.xx:51820
PublicKey = f15Cut8SWrguJaPVFp68/N+ior/yJ7q+ml2o/Q+v1zg=

NOTE:

• Android will not resolve AAAA records unless there is an IPv6 default route ² i.e. ::/0
• DNS IP corresponds with my home router. All DNS traffic from Android will get sent here while the tunnel is up.

DNS

OpenWRT supports setting hostnames for both IPv4 + IPv6 IP addresses under ‘DHCP and DNS’ -> Hostnames. I have a Truenas server on my home network, so I added 2 entries here:

Each entry corresponds with an A or AAAA record and also a PTR (reverse lookup). I’ve also configured OpenWRT with local domain .lan.

Now I’m able to connect to truenas6.lan from Android.