I work at an ISP and we're allocated many different IP blocks where we are the ultimate holder to. Recently, a new customer who would like to 'rent' a minimum of a /24 IP block wants to see there own organisation's name when doing IP lookups, whether it be on whatismyip.com or speedtest.net or whatever.
I've opened a ticket at RIPE. Naturally, they say that they have no control in what is shown on these websites or IP lookup tools. It appears that only ALLOCATED PA blocks from RIPE with an organisation attached to it are database objects where the ISP name is retrieved from.
So my question is: how does whatismyip.com know that a certain IP address is held by a certain ISP, and how can one change that?
Great question. We us IP2Location and EurkAPI as mentioned in our footer. We don't maintain our own database. I really don't know where our providers get their data from. We do have an article that explains how to correct what's shown with our providers via their support links. https://www.whatismyip.com/ip-address-geolocation-incorrect/ EurkAPI is undergoing some changes and not taking any update requests at this time so the link has been temporarily disabled.
Another IP database is maxmind. You can probably submit update requests to them as well if their data isn't showing correctly after RIPE has been updated.