Description: Table of NAT instances. As well as state and counter objects, it provides the instance index, instance name, and the last discontinuity time object that is applicable to the counters. It also contains writable thresholds for reporting of notifications and limits on usage of resources at the level of the NAT instance.

It is assumed that NAT instances can be created and deleted dynamically, but this MIB module does not provide the means to do so. For restrictions on assignment and maintenance of the NAT index instance, see the description of natv2InstanceIndex in the table below. For the requirements on maintenance of the values of the counters in this table, see the description of natv2InstanceDiscontinuityTime in this table.

Each NAT instance has its own resources and behavior. The resources include memory as reflected in space for map entries, processing power as reflected in the rate of map creation and deletion, and mappable addresses in each realm that can play the role of an external realm for at least some mappings for that instance. The NAT instance table includes limits and notification thresholds that relate to memory usage for mapping at the level of the whole instance. The limit on number of subscribers with active mappings is a limit to some extent on processor usage.

The mappable 'external' addresses may or may not be organized into address pools. For a definition of address pools, see the description of natv2PoolTable. If the instance does support address pools, it also has a pooling behavior. Mapping, filtering, and pooling behavior are defined in the descriptions of the natv2InstancePortMappingBehavior, natv2InstanceFilteringBehavior, and natv2InstancePoolingBehavior objects in this table. The instance also has a fragmentation behavior, defined in the description of the natv2InstanceFragmentBehavior object.