/etc/radiusclient/servers is in libfreeradius-client2 1.1.6-7.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 | ## Server Name or Client/Server pair Key
## ---------------- ---------------
#
#portmaster.elemental.net hardlyasecret
#portmaster2.elemental.net donttellanyone
#
## uncomment the following line for simple testing of radlogin
## with freeradius-server
#
#localhost/localhost testing123
|