CURL ERROR: Recv failure: Connection reset by peer - PHP Curl

Encountering the "CURL ERROR: Recv failure: Connection reset by peer" error in PHP Curl can be perplexing. Here's an exploration of potential causes and solutions to address this issue:

Possible Causes and Solutions

1. TCP/IP Issues:

The remote server may have terminated the connection due to a sudden drop in network connectivity. Consider checking with your hosting provider or upgrading your OS to resolve any TCP/IP-related problems.

2. Kernel Bugs:

For Linux users, there may be a TCP window scaling bug in kernels after v2.6.17. Refer to Linux bug reports for further information and ensure you're using an updated kernel version.

3. PHP & CURL Bugs:

Ensure you're using recent versions of PHP and CURL to avoid known bugs. Check for any available updates and upgrade to resolve these issues.

4. Maximum Transmission Unit (MTU):

The size of packets traversing the network connection may have changed from the default 1500 bytes. This can occur if a VPN is configured or a specific MTU setting has been implemented. Check and adjust the MTU size accordingly.

5. Firewall (iptables):

Examine your server's firewall settings. Ensure port 80 is open for incoming connections from the source IP address and that there are no rules blocking the connection in iptables.

Experimental Approach

Try a Different Server:

Test the script on a different server to rule out server-related issues. If the error persists, proceed with other troubleshooting steps.

Additional Code-Related Considerations

1. SSL:

If the remote URL uses HTTPS, proper SSL settings in your code are essential. Ensure you have OpenSSL installed and enabled, and implement the following code to handle SSL verification:

curl_setopt($c, CURLOPT_SSL_VERIFYPEER, false);
curl_setopt($c, CURLOPT_SSL_VERIFYHOST, false);

By considering these potential causes and implementing appropriate solutions, you should be able to resolve the "CURL ERROR: Recv failure: Connection reset by peer" issue in your PHP Curl script and establish a stable connection to the remote server.