- Markus Koetter made CURLOPT_FTPPORT (and curl's -P/--ftpport) support a port

range if given colon-separated after the host name/address part. Like
  "192.168.0.1:2000-10000"

docs/libcurl/curl_easy_setopt.3

@@ -1070,6 +1070,12 @@ be a plain IP address, a host name, a network interface name (under Unix) or
 just a '-' symbol to let the library use your system's default IP
 address. Default FTP operations are passive, and thus won't use PORT.
 
+Starting in 7.19.5, you can append \&":[start]-[end]\&" to the right of the
+address, to tell libcurl what TCP port range to use. That means you specify a
+port range, from a lower to a higher number. A single number works as well,
+but do not that it increases the risk of failure since the port may not be
+available.
+
 You disable PORT again and go back to using the passive version by setting
 this option to NULL.
 .IP CURLOPT_QUOTE