Fixing cURL Error 7: Failed to Connect to Port 443

What is cURL Error 7?

cURL Error 7 means that the TCP link to a certain host and port failed. When your server tries to connect to another server, it uses ports to help the two servers talk to each other. Port 443 is often used for HTTPS transactions that need to be safe. If the link to this port fails, cURL error 7 happens, and an error message is sent.

When Does cURL Error 7 Occur?

cURL error 7 can happen in many different situations, but one common one is when your website or app is trying to connect to external services, like APIs or remote servers, but is having trouble making the link. This error can happen when you try to do things like send HTTP requests or get info from sources outside of your computer.

Diagnosing the Exact Scenario of the Error

To fix cURL error 7, you need to find out why it’s happening. Let’s look at a real-world situation in which one of our WordPress customers ran into this error.

Scenario: Resolving cURL Error 7 in WordPress

Recently, one of our WordPress users had trouble activating a theme on their website. When they looked into why the theme validation process failed, they found a cURL error 7.

Troubleshooting and Solution

Our help engineers jumped in right away to figure out what was wrong and fix it. Here are the steps to do it:

1. Making sure the outgoing connection and firewall settings are correct
   First, our engineers made sure that no firewall was blocking links from the server to the outside world. They made sure that port 443 was open for TCP In/Out and UDP Out for both IPv4 and IPv6.
2. Checking for IP Blocking
   After doing more research, our team found that the WordPress theme update server had stopped the customer’s IP address. During the approval of the theme, the cURL error 7 was caused by this block.
3. Whitelisting the IP Address
   To fix the error, our support team told the customer to talk to the managers of the theme update server and ask for their IP address to be added to the whitelist. After the IP address was added to a “whitelist,” the cURL error 7 went away, and the theme registration went off without any issues.

Conclusion

In short, cURL error 7 failed to connect to port 443 usually happens when the firewall stops the curl request. Today, we’ve talked in depth about this mistake and seen how our Support Engineers fix it for our customers.