Single and static IP on rDNS

Greetings -

Our credit card processor is asking for the IP (vs FQDN) where transactions originate so as to whitelist it. I am not sure as to how often cloudflare changes the dynamically allocated IP but what is certain is that nslookup returns two IP’s - which seems more than what the CC processor can handle

Is there a workaround allowing for a single and static IP on rDNS?


Transactions aren’t going to originate here. They’ll come from your server’s IP address.

Their suggestion on using FQDN is probably just to make it easier for people who don’t know how to look up their server’s IP address.


My understanding is that for all practical purposes, unless I specifically browsed to my IP, traffic to/from my FQDN was channeled through cloudflare, so that when browsing (or ordering a purchase) on my FQDN, the visible IP is cloudfalre’s - am I mistaken?

Have you actually tried inputting your server’s IP address? I’d hope there’s a built in test to see if it’s working.

My server’s IP will not work but that is to be expected: anything that was not whitelisted on the CC processor’s side will be rejected - and they specifically asked for the FQDN and IP - I gave one of the two cloudflare’s IP showing up on nslookup since they dont allow more than 1 IP

Next steps is indeed to give server’s IP, but I would still like to know if my understanding of how cloudflare IP get in the mix - in case my server’s IP does not work and they somehow look for a match between FQDN and rDNS

Thanks for bearing with me :slight_smile:

rDNS of those Cloudflare IP addresses won’t work either, as you don’t own the IP address(es) of your FQDN.

Right! Hence my question as to a workaround to get (purchase from Cloudflare?) a single / fixed IP for my FQDN to resolve to.

With an Enterprise Plan, pretty much anything is possible, but that’s thousands of dollars per month.

I wish I had that kind of budget :frowning:

The transaction from the server to your CC processor will be from your server IP, Cloudflare IPs appear from the user to your server.


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