Question posted in 
I have a website deployed in Netlify and I have a form that submits a POST request to a webhook in Integromat.
The webhook works but I want to add IP restriction to the webhook so that no else can use the webhook. Integromat is asking for an ip but I can’t seem to find what ip address to use, is there a way to find the ip I need like in Cpanel?
I tried using my domain e.g website.com or https://www.website.com. And I got a 400 error.
I also tried using netlify’s load balancer ip 104.198.14.52 and it didn’t work :C.
I tried an online dig tool and I got something like:
id 25009
opcode QUERY
rcode NOERROR
flags QR RD RA
;QUESTION
staging.socialspacecoworking.com. IN A
;ANSWER
staging.socialspacecoworking.com. 3599 IN CNAME socialspacecoworking-web.netlify.com.
socialspacecoworking-web.netlify.com. 19 IN A 142.93.122.177
;AUTHORITY
;ADDITIONAL
But the thing is if I try to run dig a couple times. the address 142.93.122.177 will change to something else.
Thank you so much,
2
Answers
Netlify (and similar services like Heroku, etc) uses rotating IPs, so this likely won’t be possible.
An alternative would be to include an API key in the request, that you could sign/verify with a key you keep in data store.
This is a couple of years old, but I just wanted to point out that this won’t work. If your FORM is in a webpage, than the POSTer’s IP is not the server’s IP, it’s the IP of the web browser client.
The HTTP POST connection is from that user, directly to your Webhook. Your netlify server just delivered the HTML Form. The submit doesn’t go through your webserver to get to its action="" destination.