eap Mailing List: Basic facts about EAP

[Bernard Aboba (aboba]

I have received a request that the following basic facts about EAP be
posted to the EAP WG mailing list.

a. EAP is a two party protocol, run between an EAP peer and server.
Saying EAP is an N-party protocol is like saying that TCP is a
N-party protocol because TCP packets pass through routers.  Forwarding
an EAP packet without modification does not cause an entity to become a
"participant" in an EAP conversation any more than forwarding an IP packet
turns a router into a host.

b. EAP can travel over any lower layer transport meeting the requirements
of RFC 3748 Section 3.1.

c. An EAP peer or authenticator can have multiple ports.  EAP
lower layers that confuse the authenticator (or peer) with its ports are
a bit like a person who shakes hands with both arms of someone they
meet because they don't look at the head attached to the hands they are
shaking.  EAP exchanges occur between the EAP peer and server, not between
ports of the EAP server and authenticator.  Similarly, the AAA-Key is
shared by all ports of an authenticator and peer.