From Yuriy Volokitin:
LanTopolog is an application that provides physical network topology discovery, visualization and monitoring. The key features are automatic physical network topology discovery based on SNMP. Provide detailed and searchable physical network topology map so you can quickly isolate network connectivity failures. Topology views show which network devices are connected to each switch port connections are labeled with port numbers. Ability to auto-discovery new devices at them is added to your network. LanTopolog also includes network monitoring tools. It is monitoring device's state (active/inactive) in real-time using ICMP. It is also Network traffic monitoring. It is generating alarms when there are failures in the network. E-mail alerts notifying. It is Web browser-based access from anywhere in the network.