I was using ipaddr = domain_name in the home_server definitions. I remembered a problem I had with the freeradius client library wherein if I used a domain name, like localhost, instead of a "real" IP address to describe the server I needed to connect with, I'd get a failure.
Using the same proxy.conf file I sent in my first note and changing the ipaddr variable to 127.0.0.1 instead of localhost for each home server allowed me to successfully connect to the primary radius server. I won't have a secondary server set up until next week, at which time I'll test if the fail over to the secondary server work. As I fully expect it to.
I assume it is a bug to be required to use and IP address instead of a domain name, so can you please point me to where I can file a bug report on this?
It's not a bug. Hostname lookups are disabled by default in radiusd.conf. Along with explanation why enabling it is a bad idea. Ivan Kalik Kalik Informatika ISP