In the Boundaries and subnet sections I have specified only one boundary and one subnet.
The devices that were being authenticated to all seem to be outside of these boundaries and subnet. How come devices outside of the boundaries and subnets we specified are being contacted by Parallels?
The option 'Search local subnets’ was enabled. This caused such behavior (scanning of all subnets available from local interfaces of the machine where Proxy Configuration Manager installed
We would recommend you to NOT turn on 'Search local subnets’ in case this is not required.