This object is used to get/set the validity of the information
contained by nbsNtpServerEntry row.
Setting this object to the value invalid(1) has the effect of
deleting the corresponding nbsNtpServerTable entry. Deleting
and entry has the effect of initializing it to default values :
IpAddr = 0.0.0.0
Setting this object to the value valid(2) entry has the effect of
creating a new row in the nbsNtpServerTable object, if an entry
with the same nbsNtpServerIpAddr does not exist. If such an
entry exists, then a 'badValue' error will be returned.
The GET operations will receive a value of valid(2) for existing
entries. An invalid(1) value indicates an entry that was deleted by
a previous SET operation.