Failed to check if server netblock is added to the cPGreyList trusted hosts: WHOIS lookup failed

Symptoms

When accessing the WHM module Greylisting's "Trusted Hosts" tab, the following error is generated via the UI:

Failed to check if server netblock is added to the cPGreyList trusted hosts: WHOIS lookup failed

Description

This issue relates to your server's ability to query WHOIS, which utilizes the outbound TCP port 43.

We've opened an internal case for our development team to investigate this further. For reference, the case number is CPANEL-47074. Follow this article to receive an email notification when a solution is published in the product. 

Workaround

Please ensure that the outbound TCP port 43 has been enabled in the server's firewall and networking. We have the following documentation covering how to configure your firewall for cPanel services:

cPanel & WHM Documentation - How to Configure Your Firewall for cPanel & WHM Services

Also, once the firewall connection has been resolved, you can remove the cache file to refresh the list manually.

1. To Remove the cache via SSH/Terminal:

mkdir /root/cptechs/

mv /root/.cpanel/datastore/Cpanel\:\:Net\:\:Whois\:\:IP\:\:Cached_* /root/cptechs/

2. To refresh the list manually via SSH/Terminal:

whmapi1 cpgreylist_is_server_netblock_trusted

3. You can also reload the browser tab in the WHM UI for Greylisting's Trusted Hosts to refresh.