Blynk Network Port Forward Config

2 min readJul 2, 2021

Port forwarding & proxy config for Blynk Server

I’m using blynk server (local) to monitor the state-of-charge of a battery that’s connected to a solar panel.

To get the app working from inside the local network and outside when I’m travelling, we need to configure DNS and port forwarding as follows.

Note 1:

the admin pages are accessed over https on port 443
the app uses a proprietary protocol (not http) also on port 443…!

Note 2:

please decide for yourself whether exposing this service to the internet is a good thing…? Perhaps you prefer a VPN solution, then your device can simply access internal services when connected.

Tools

DNS external and internal (dnsmasq on docker)
router — internet connection, port forwarding
nginx (docker) — proxy traffic to the blynk server
Blynk Server (local, docker) — note, local server is now deprecated. Blynk.io decided to discontinue the product.
apache — I was not able to get apache to proxy the stream

External DNS

blynk.home.com => 123.123.123.123 (my external ip address)

Internal DNS

blynk.home.com => 10.0.0.25 (internal ip of server on vm/docker)
nginx.home.com => 10.0.0.24 (internal ip of nginx)

Router port forwarding

8080 => blynk.home.com:80 (optional, if you want devices in the wild)
8444 => nginx.home.com:8444 (stream, for the app)
8443 => nginx.home.com:8443 (https, for admin pages)

nginx config

Forward both 8444 (blynk proto) and 8443 (https) to the Blynk server

events {}stream {
    upstream blynkserver {
        server 10.0.0.25:443;
    }
    server {
        listen           8444;
        proxy_pass       blynkserver;
    }
}http {
    server {
        # Server configuration
        listen 80 default_server;
        return 301 https://$host$request_uri;
    }    server {
        server_name blynk.home.com;
        listen 8443;
        ssl on;
        ssl_certificate ssl/blynk.home.com.cert.pem;
        ssl_certificate_key ssl/blynk.home.com.privkey.pem;
        ssl_session_cache  builtin:1000  shared:SSL:10m;
        ssl_protocols  TLSv1 TLSv1.1 TLSv1.2;
        ssl_ciphers HIGH:!aNULL:!eNULL:!EXPORT:!CAMELLIA:!DES:!MD5:!PSK:!RC4;
        ssl_prefer_server_ciphers on;
        location / {
            proxy_ssl_verify off;
            proxy_pass https://10.0.0.25:443/;
        }
    }
}