On the Extreme device, the SNMP server host serves as a trap receiver to ensure that all SNMP traps sent by the device go to the same SNMP trap receiver or set of receivers, typically one or more host devices on the network.
For an SNMPv3 trap, you associate a SNMPv3 host with the SNMP users. When you specify the host, you also specify a community string for SNMPv1 and SNMPv2. The Extreme device sends all the SNMP traps to the specified hosts and includes the specified community string. Then, administrators can filter for traps from a Extreme device based on IP address or community string.