What are the limitations of using Curl to access a site in terms of IP address manipulation?

When using Curl to access a site, the limitations of IP address manipulation are that Curl does not natively support setting a specific IP address for the request. However, this can be overcome by using a proxy server that allows you to specify the IP address you want to use for the request.

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, 'http://www.example.com');
curl_setopt($ch, CURLOPT_PROXY, 'http://your-proxy-server-ip:port');
curl_setopt($ch, CURLOPT_PROXYTYPE, CURLPROXY_HTTP);
curl_setopt($ch, CURLOPT_PROXYUSERPWD, 'username:password');
$response = curl_exec($ch);
curl_close($ch);