CHAPTER 1: INTRODUCTION
1.10.6Operation of the Subnet Mask
The Subnet Mask defines how your EMM-E6 treats SNMP Trap IP destination addresses in its Trap table (see Chapter 7, Trap Table Screen, for additional information on traps).
When using the Subnet Mask, the EMM-E6 logically determines one of two possible locations, either on or not on its own subnet, for each Trap IP destination address in its trap table. If the address is on its own subnet, the EMM-E6 transmits directly to the workstation with that address. If the address is not on its subnet, the EMM-E6 transmits to the workstation with that address combined with the Default Gateway IP address. Default Gateways are discussed later in this chapter.
Modify the default Subnet Mask for the EMM-E6 when workstations in the Trap table reside on a different subnet (i.e., across a gateway or external router), and you want these workstations to receive SNMP Traps generated by the EMM-E6. Caution should be exercised when configuring subnets, as a poorly subnetted network can greatly increase network traffic by duplicating transmissions.
1.10.7Default Gateway
The Default Gateway is the IP address of the network or host to which all packets addressed to unknown networks or hosts are sent. The Default Gateway should be a perimeter or border device that connects the network with the rest of the world. The Default Gateway attempts to route the packet to the correct destination. This gateway is often used by managers to handle all traffic between private networks and the Internet. If a Default Gateway is not defined, the packets addressed to a network or host address not found in the forwarding table will be dropped.
