The value of tmnxRadProxSrvLoadBAttr4 specifies
a RADIUS attribute that must be used
to construct the key for load-balancing RADIUS messages
between RADIUS servers while the value of the object
tmnxRadProxSrvLoadBalanceKey is equal to 'attributes'.
While the value of tmnxRadProxSrvLoadBalanceKey is different
from 'attributes', the value of tmnxRadProxSrvLoadBAttr4 must
be equal to zero.