Here's a random post I just found: https://gist.github.com/brasey/fa2277a6d7242cdf4e4b7c720d42b...
(Ha, I did the thing where I read the comments before the post, and the post describes how to do this. So what's still missing?)
What, I think, you really care about here is glibc's behavior. But then, you can't depend on any one libc, either.
https://github.com/containernetworking/cni
https://github.com/firecracker-microvm/firecracker-go-sdk
Firecracker, by design, only supports Linux tap devices. The SDK provides facilities to:
Attach a pre-created tap device, optionally with static IP configuration, to the VM. This is referred to as a "static network interface".
Create a tap device via CNI plugins, which will then be attached to the VM automatically by the SDK. This is referred to as a "CNI-configured network interface"