Network Address Translation (NAT) involves translating the source and or destination IP addresses of packets as they traverse from one IP domain to another. NAT is usually performed on packets that are routed, and there is a MIB already defined for that, but the application addressed here is for performing NAT for Layer 2 switched packets. This MIB module defines objects and tables for Network Address Translation (NAT) performed at layer 2. This application is planned currently for Industrial Ethernet switches, but this could be used for other applications. This platform implements NAT using an FPGA which connects to uplinks, so NAT is only applicable for packets coming in from uplinks, and going out of uplinks. There are 3 main logical modules that are referred in this MIB. Global parameters : These provide statistics for the entire platform. L2NAT Instance Table : This table contains multiple Layer 2 NAT instances. A Layer 2 NAT instance referred throughout this MIB is an entity that is defined with respect to the Layer 2 NAT feature, and is different from the concept of instance as used in SNMP. Each Layer 2 NAT instance has a unique number. Each Layer 2 NAT instance consists of packets that are to be permitted or denied, as well as packets that are supposed to be fixed up. Fixup is a NAT concept which applies to certain applications which embed IP addresses in the payload. For these applications to work across NAT, the embedded IP addresses need to be translated along with the header IP addresses. Each Layer 2 NAT instance also contains a list of source and/or destination IP address translations An instance only becomes effective on traffic after being applied to an interface vlan combination. This table actually consists of these 2 MIB tables in order for indexing to work, cl2natInstanceTable and cl2natInstanceIpTable L2NAT Interface Config Table : This table contains multiple entries, where each entry contains configuration for the instance applied to an interface vlan combination. This table actually consists of these 2 MIB tables in order for indexing to work cl2natInterfaceConfigTable and cl2natInterfaceIpConfigTable. L2NAT Interface Statistics Table : This table contains multiple entries, where each entry contains stats for the instance applied to an interface vlan combination. This table actually consists of these 2 MIB tables in order for indexing to work , cl2natInterfaceStatisticsTable and cl2natInterfaceIpStatisticsTable.