In the absence of proper next-hop state derivation, some interesting
concepts have been introduced by eduroam participants -- the most
noteworthy being a failover logic that considers up/down states not
per next-hop RADIUS peer, but instead per realm (See [dead-realm] for
details). Recently, implementations of RFC 5997 [RFC5997] and
cautious failover parameters make false "downs" unlikely to happen,
as long as every hop implements RFC 5997. In that case, dead realm
detection serves mainly to prevent proxying of large numbers of
requests to known dead realms.