SNMP is widely used by network administrators to monitor and administer all types of computers (e.g., routers, switches, printers). SNMP uses an unencrypted "community string" as its only authentication mechanism. Attackers can use this vulnerability in SNMP to possibly gather information from, reconfigure or shut down a computer remotely. If an attack can collect SNMP traffic on a network, then he can learn a great deal about the structure of the network as well as the systems and devices attached to it.

Disable all SNMP servers on any computer where it is not necessary. However, if SNMP is a requirement, then consider the following. Allow read-only access and not read-write access via SNMP. Do not use standard community strings (e.g., public, private). If possible, only allow a small set of computers access to the SNMP server on the computer.

Network Security Testing
Test regularly the security of all of the following computers on the network: clients, servers, switches, routers, firewalls and intrusion detection systems. Also, do this after any major configuration changes on the network.