I want to ping devices outside of azure boundaries. We have an Azure VM with NIC and with Azure VM we are able to ping the devices. But that VM don't have any public IP but still able to ping the devices. The only difference between our Azure Function is the NIC, so I want to know is this the root cause which is blocking the ping to devices. Since I am new to networking, can someone please update me that why VM has NIC by default but function app doesn't?
And do have we any way to add NIC to function app or to add function app to NIC?
Added Private End Points and VPN to azure functions
For the ICMP issue, I found this: https://www.liammoat.com/blog/2016/azure-app-services-ping-with-kudu/. I don't think App Services (which includes Functions) allow ICMP at all. That's also why they include the "tcpping" tool. I could be wrong about this though as I didn't find any very recent info on this.
Since I am new to networking, can someone please update me that why VM has NIC by default but function app doesn't?
There is a dynamic number of VMs under the hood that the Function App can run on. I think VNET Integration sets up the NICs in the subnet you provide it (or something similar to the NIC anyway). Those are not visible to you, an IP address is taken per instance from the subnet.
And do have we any way to add NIC to function app or to add function app to NIC?
No.