Apps and containers are often given only a port to listen on, like port 80, without additional constraints like host or path. HTTP_PORTS and HTTPS_PORTS are config keys that specify the listening ports for the Kestrel and HTTP.sys servers. These keys may be specified as environment variables defined with the `DOTNET_` or `ASPNETCORE_` prefixes, or specified directly through any other config input, such as `appsettings.json`. Each is a semicolon-delimited list of port values, as shown in the following example:

```
ASPNETCORE_HTTP_PORTS=80;8080
ASPNETCORE_HTTPS_PORTS=443;8081
```

The preceding example is shorthand for the following configuration, which specifies the scheme (HTTP or HTTPS) and any host or IP.

```
ASPNETCORE_URLS=http://*:80/;http://*:8080/;https://*:443/;https://*:8081/
```

The HTTP_PORTS and HTTPS_PORTS configuration keys are lower priority and are overridden by URLS or values provided directly in code. Certificates still need to be configured separately via server-specific mechanics for HTTPS.