Internet Investing Internet Technology Internet Lists Windows Internet Tech. After installation, most SNMP managers begin with discovery, using probes to locate and identify every device in the network to be managed. All others can discover any device that answers an ICMP ping. WhatsUp Gold and SNMPc use more sophisticated router-based methods to speed discovery in larger networks.
Several products can discover services running on devices by scanning for listening ports.
But even well-intentioned port scans can trigger intrusion detection and firewall alarms and must be used with care. Port scanning is appropriate when you plan to use the NMS for service-level monitoring. Limiting discovery by IP address range or subnet can avoid searching networks that you don't own or control. The others used discovery to populate maps, typically as a hierarchy of connected subnets. A root map provides an eagle-eye view, while subordinate maps are used to drill down and isolate problems.