Advanced settings
TLS fingerprint, MTU, domain detection, parallel TCP connections, keep-alive, core log level and the full configuration view.
The Advanced section of the Connection page changes how the core treats the servers in your subscription. For most settings the default value, As in profile, changes nothing: the subscription decides. Like other connection settings, they are read when the connection starts.
| Setting | Default | Options |
|---|---|---|
| TLS fingerprint | As in profile | chrome, firefox, safari, ios, android, edge, 360, qq, random, randomized, chrome120, firefox120, safari16 |
| MTU | Auto | Auto, 1280, 1400, 1500 |
| Domain detection (sniffer) | As in profile | As in profile, On, Off |
| Parallel TCP connections | Off | On, Off |
| Keep-alive | As in profile | As in profile, 30 s, 120 s, 300 s, Off |
| Log level (Core log section) | info | silent, error, warning, info, debug |
TLS fingerprint
Chooses the browser TLS fingerprint the core presents to servers. When you pick a value, an extra switch Override the profile’s value appears. Off (default), the value is applied only to servers that have no fingerprint of their own. On, it replaces the fingerprint set in the profile.
MTU
The maximum packet size of the tunnel. Auto uses the platform value (1280 on Android). Applies to TUN mode on Windows and macOS and to the VPN service on Android. Lower it only if some sites hang while others work.
Domain detection (sniffer)
Lets the core detect the domain name inside a connection so domain rules can match connections that start from an IP address. As in profile keeps whatever the subscription says.
Parallel TCP connections
When on, the core tries several addresses of a server at once and uses the first that answers. Off by default.
Keep-alive
How often idle connections send keep-alive packets. Less frequent or off saves battery on laptops and phones.
Log level
The detail of the core log (Core log page). info is the default; debug is the most verbose and is useful when reporting a problem. The log stays on your device.
Full configuration
Settings → Full configuration shows the YAML that the core actually runs. Switch Version between With my rules (your profile plus your custom rules) and Original (exactly what the provider sent). Use search to find lines and Copy to copy the whole text. A provider can hide this page with the letakof-view-config header, see Additional headers.
Found a mistake? Open an issue on GitHub.