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► Multicast propagation
If authentication occurs in the core of the LAN, it is necessary for local access
bridges to forward authenciation traffic toward the core so that the
authenticator can respond. Because core bridges are not able to sense the
end-station connection to the local access bride port, initiation of
authentication can occur either on receiving traffic from a new end station or
through end-station inititation. Requiring a core bridge to maintain
authentication state for each end station does not scale. In order for
end-station initiation to reach the core bride, this requires that these
(multicast) frames be flooded by authenciation-unaware access bridges,
impatient other end stations. In contrast, if authentication occurs only on local
access bridges, these multicast frames are not forwarded.
23.4 RFCs relevant to this chapter
The following RFCs provide detailed information about network admission
control as presented throughout this chapter:
► RFC 2716 – PPP EAP TLS Authentication Protocol (October 1999)
► RFC 2865 – Remote Authentication Dial in User Services (RADIUS)
(June 2000)
► RFC 3748 – Extensible Authentication Protocol (EAP) (June 2004)
► RFC 4017 – Extensible Authentication Protocol (EAP) Method Requirements
for Wireless LANs (March 2005)
► Internet-Drafts Database Interface – EAP over UDP (EAoUDP)
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