Connecting ESPHome node to Home Assistant across a Wireguard VPN

ESPHome
7

Thanks for your suggestion, this is the current config for each router:

Router at 192.168.10.1:

[Interface]
PrivateKey = XXX
ListenPort = 50525
Address = 192.168.10.1/24
DNS = 192.168.10.1,192.168.20.1
DNS = fritz.box

[Peer]
PublicKey = XXX
PresharedKey = XXX
AllowedIPs = 192.168.20.0/24
PersistentKeepalive = 25


Router at 192.168.20.1:

[Interface]
PrivateKey = XXX
ListenPort = 55977
Address = 192.168.20.1/24
DNS = 192.168.20.1,192.168.10.1
DNS = fritz.box

[Peer]
PublicKey = XXX
PresharedKey = XXX
AllowedIPs = 192.168.10.0/24
Endpoint = XXX.myfritz.net:50525
PersistentKeepalive = 25

According to your description, that should be correct?

I noticed that I can reach 192.168.10.1 from 192.168.20.x, but I can’t reach 192.168.20.1 from 192.168.10.x. This explains why Home Assistant, which lives in 192.168.10, gets no updates from the ESPHome node in 192.168.20.x. The WireGuard Tunnel is basically unidirectional, and I don’t understand why.

Update: I think my ISP uses CGNAT, maybe this is causing issues.