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Comment by dajt | Hacker News Reader

Can anyone ELI5 how two additional OSs can run network stacks without interfering with each other and the user OS networking?

I assume ME and UEFI use DHCP to get their addresses yet my modem/router only shows the one from my user OS.

Where do they get the drivers for whatever NIC happens to be installed? Do the motherboard vendors have to put blobs in place during manufacturing?

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If the stacks each get transport layer copies of what's incoming and the hidden stack gets to also see all that is outgoing and produce its own frames, it should not be hard, and I think that's the level of interference we should assume at least. The hidden stack could listen in on DHCP communication to figure out what address to assume and act on any incoming packets as necessary, and until it actually sends something it would be invisible to your network. When it does send something it could then easily be with one of the addresses assigned to the non-hidden stack.

It is not much different in concept from a normal layer 1 switch. Everything gets repeated and the recipients discard what they're not interested in.

The fact that ME and UEFI have network stacks doesn't mean that they are always active. And yes there is nic support embedded in the firmware. This is how you're able to pxe boot or bring up the nic after booting EFI shell for example.

To get the network capabilities of the ME, the machine has to have a compatible NIC, AFAIK.

This is a good reason to buy a machine that is not all Intel (or all anything else)

I'd like to know about this, too.

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