This object indicates the (first) network layer address at
which the device will accept SNMP messages as reported in the
most recently received CDP message. If the corresponding
instance of cdpCachePrimaryMgmtAddrType has the value 'ip(1)',
then this object would be an IP-address. If the remote device
is not currently manageable via any network protocol, this
object has the special value of the IPv4 address 0.0.0.0.
If the most recently received CDP message did not contain any
primary address at which the device prefers to receive
SNMP messages, then this object is not instanstiated.