You can’t bind nginx to a specific network interface.

You can bind it to a specific IP address though (and then, by extension, also to an interface, but you need to know the IP).

That's right, although I am struggling to think of use cases where you may need to assign it to network interface with dynamic IP allocation (otherwise you'd know the IP beforehand).

> although I am struggling to think of use cases where you may need to assign it to network interface with dynamic IP allocation

Some failover configurations come to mind, in particular the one where the box doesn’t get an IP address on the said interface until the failover kicks in, but I don’t know why would anyone run this kind of a setup without NAT.

I did that bind with DHCP server failover.

My use case is simple.

I have five disparate IP subnets whose firewall must NOW have to ascertain that ONLY a certain subnet can access this unbinded netdev … in case the NGINX (or any daemon) starts to sniff unwarranted IP subnet traffic.

And yes, you can bind to a dynamic IP assigned netdev.

And yes , I’ve had to replace NGINX with a web server that can do a netdev bind.