Ask HN: Intel ME countermeasure idea

Quick question about an Intel ME countermeasure that just occurred to me:

Modify the Linux network stack to add an identifiable tag to every outgoing packet, pass all traffic through a firewall running on a pre-2006 laptop that drops packets without the tag, and change the tag more frequently than the ME can adapt.

Can any knowledgeable network programmers comment on the feasibility before I get too carried away with the idea?