CURLOPT_FTP_SKIP_PASV_IP - ignore the IP address in the PASV response

Added in curl 7.15.0

1 since 7.74.0, was 0 before then.

Pass a long. If skip is set to 1, it instructs libcurl to not use the IP address the server suggests in its 227-response to libcurl's PASV command when libcurl connects the data connection. Instead libcurl reuses the same IP address it already uses for the control connection. It still uses the port number from the 227-response. This option allows libcurl to work around broken server installations or funny network setups that due to NATs, firewalls or incompetence report the wrong IP address. Setting this option also reduces the risk for various sorts of client abuse by malicious servers. This option has no effect if PORT, EPRT or EPSV is used instead of PASV.

int main(void) { CURL *curl = curl_easy_init(); if(curl) { CURLcode res; curl_easy_setopt(curl, CURLOPT_URL, "ftp://example.com/file.txt"); /* please ignore the IP in the PASV response */ curl_easy_setopt(curl, CURLOPT_FTP_SKIP_PASV_IP, 1L); res = curl_easy_perform(curl); curl_easy_cleanup(curl); } }

CURLOPT_FTP_SKIP_PASV_IP - ignore the IP address in the PASV response

This functionality affects ftp only

curl_easy_setopt(3) returns a CURLcode indicating success or error. CURLE_OK (0) means everything was OK, non-zero means an error occurred, see libcurl-errors(3).

CURLOPT_FTPPORT(3), CURLOPT_FTP_USE_EPRT(3) libcurl 2025-06-16 CURLOPT_FTP_SKIP_PASV_IP(3)

#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_FTP_SKIP_PASV_IP, long skip);