Answer

[Stefan Winter]

> Does Freeradius have the ability to use multiple nodes in similar fashion
> to name servers?  An example of this would be a situation when the master
> freeradius server is down for some reason, but the slave freeradius
> server(s) continue to grant & deny access but do not receive any updates
> until the master is back up.

You can simply set up more than one FreeRADIUS instance. Then you have to tell 
your clients that more than one authentication server exists - pretty much 
the same as with DNS. But as with DNS, you should pay attention on how your 
clients will recover in case of a failure. Some may for example eternally use 
the "slave" even when the "master" is back up again. The reasons I use quotes 
is that there is no concept of superiority of one server vs. the other - they 
are just two equal alternatives to the client.

For the "won't receive any updates" I'm not sure what you mean.

> Also, if there are any HOWTO or example configurations of this type of
> setup, those would be very helpful.

Just setup the server twice (ideally both using _one_ authentication backend, 
e.g. a mySQL db on a different host that both can access) and tell your 
client devices about it.

Greetings,

Stefan Winter

-- 
Stefan WINTER

Fondation RESTENA - Réseau Téléinformatique de l'Education Nationale et de 
la Recherche - Ingénieur de recherche

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