I am having a problem too where the network goes into a mode where the
Portmaster returns "Host Unavailable" and authentication requests do not
seem to be reaching the RADIUS server, authentication for the users stored
in the Portmasters user table still function normally.
Most of the time the RADIUS authentication works correctly but when this
problem occurs it will stay that way for an hour or more but eventually
starts working again without anything being done to it.
I believe I have been able to ping between the two when in this mode but I
will reconfirm that. I am also running DNS and email services on the RADIUS
machine (all on the same NIC) and they continue to function when this
problem hits.
The traffic on my LAN is also light.
Jim