It seems like some eyeball and distribution networks should get together and run a private subset of the Internet, with good filtering (BCP38 style), etc. internally. You could get pretty good coverage with just ~10 eyeball networks in the US, a few cloud providers, and maybe some key infrastructure. Operate normally most of the time, but when under attack, be able to fall back to just vetted networks, transports, and routes, at least temporarily. Then have a limited number of hardened gateways, the way NIPRnet does with the civilian commercial Internet, which are used in intermediate-level attacks.<p>Opt-in, maybe have an association run it (like an IX, but without the expensive dinners and dues and general activism which inflates IX budgets), etc. This would do more for "critical infrastructure protection" than anything DHS/NSA/FBI have ever done.