Ken Calvert* University of Kentucky *Speaking for myself only

The Internet Protocol (v4) is at best useless, and at worst harmful, in home networks consisting of a NAT-ed, single broadcast domain. (Belief: this covers most cases.)

Internet NAT Gateway/ Bridge/Router

 Inside clients don’t know (or need to know) anything about their own IP addresses  IP functionality is superfluous  Single broadcast domain  bridging suffices  MAC addresses provide both ▪ Global uniqueness ▪ Technology-independence  Inside IP addresses are meaningless outside  Name resolution (if any) can/should use MAC addresses

 Requires that the user act as network administrator  Choose: static addressing or DHCP?  Network prefix?  Where is my DHCP server(s)?  Endpoints must allow configuration  endpoints can be misconfigured  E.g., someone changes host to a static IP address  Now the user must also diagnose the problem! ▪ With inadequate tools ▪ No way to “RESET” the whole network!

Third option: “Ignore IP”  Should be the default  Force user to say “I know what I’m doing” to use any other option (static assignment or DHCP)  Let endpoints use arbitrary IP addresses  Local-scope addresses for uniqueness  Transport demux still works  Identify endpoints with MAC addresses  Inside applications  Ethernet was designed for this! Note: already happening in data centers

 Rely on MAC addresses  Establish identities/function of devices  Switch based on MAC addresses  Infer (some) intent from port numbers  Partial prototype implementation  “HomeRun” [Hasan, Edwards, Feamster, Calvert]  Built on NOX Box platform  Todo: mechanism for establishing identities/functions and getting to a “known good” state