Pingbacks not working in WordPress? It’s not just you. In the past, I have worked with multiple clients who had the same issue.
Many site owners consider pingbacks and trackbacks to be important SEO factors. It is therefore important that these things work correctly on a WordPress installation.
Since WP version 2.7, there has been a known issue with pingbacks. But it is unlikely that the WordPress team will make adjustments to fix the problem because the current settings are stable under most circumstances. Please refer to this WordPress Trac ticket for more information.
In most cases, the pingback problem is not caused by a misconfigured server or website. A TimeOut variable for the ping (since 2.7, this value is 0.01 seconds) may not work well for some websites. It is not uncommon for some servers to fail to ping within 0.01 seconds.
Solution to the Pingback Problem
WordPress pingback timeouts are found in the file “wp-includes/cron.php” (not to be confused with the wp-cron.php). Line 229 contains the timeout value.
$ cron_url = get_option ('siteurl'). , /wp-cron.php?doing_wp_cron ';
wp_remote_post ($ cron_url, array (, timeout '=> 0.01,, blocking' => false, 'sslverify' => apply_filters (, https_local_ssl_verify ', true)));
Changing the current timeout value (0.01) to 1 should resolve the issue.
$ cron_url = get_option ('siteurl'). , /wp-cron.php?doing_wp_cron ';
wp_remote_post ($ cron_url, array (, timeout '=> 1,' blocking '=> false,' sslverify '=> apply_filters (, https_local_ssl_verify', true)));