How secure are IP restrictions on Azure functions ?

Question

I'm setting up an Azure function that should only be accessible from two networks. I've configured the function with ip restrictions limiting access to the two outgoing IPs of those networks. What I'm wondering is how secure is this solution ? How difficult would it be for potential intruders to fake their origin IP to get around this ? In addition to IP restrictions the function app uses Azure AD to authenticate clients.

Answer 1

Hi @Steinar Dahl

It is a good security measure.

Even if somebody spoofs your IP address to try and authenticate, they would not receive the packets back as they would route through the internet to the correct address and then most likely get dropped by your device / network.

Hope that helps.

Kind regards,

Jamie Sabbatella