Question:
What IP addresses do I need to add to my firewall?
What IP addresses do you use to send requests to my MO or DLR webhook URL?
Can I use a firewall and still receive inbound requests from you?
I am not receiving callbacks to my HTTP server. Why might this be?
Answer:
If you are restricting inbound traffic, including status reports and delivery receipts, please whitelist the following subnets:
169.50.200.65 -169.50.200.64.78 (169.50.200.64/28)
169.63.86.161 - 169.63.86.174 (169.63.86.160/28)
119.81.44.1 - 119.81.44.14 (119.81.44.0/28)
in your firewall.
Inbound SMS traffic from Nexmo might come from any of the IP addresses included in the referenced subnets.