Route Explorer, Route Dynamics take new network mapping path

Most network administrators would give their right arms to get an accurate picture of their network over time. Knowing where the network is broken can save hours of troubleshooting, which translates into monetary savings for any enterprise. Creating a dynamic network map is a good solution, but most devices that gather that data ignore the one device that can tell them everything: routers.

Traditional network monitoring packages treat the network as a group of devices that happen to be interconnected. As a result, routing information tends to be interpreted on a device-by-device basis, making troubleshooting difficult.

Luckily, an emerging class of network mapper is changing that by using existing routers and routing protocols to gather network information. Two early entries, Packet Design’s Route Explorer 1.5 and Ipsum’s Route Dynamics 1.2 network monitoring packages treat the network as a large interconnected system, collecting  routing information for analysis.

This new approach allows administrators to monitor the network in terms of traffic paths and connections, making sure relevant network paths are available to users. With the stored information, administrators can “replay” the state of the network from a point in the past to make diagnoses.

Because Route Explorer and Route Dynamics get data directly from the routers, their network maps are more accurate. Plus, both systems are almost entirely passive, and neither requires router reconfiguration to integrate into a network.

The differences, however, lie in the products’ user interfaces and architecture: Route Dynamics is more distributed, Route Explorer is centrally managed. Though both are very good, Route Explorer’s extra features, including its what-if analysis tools, give it an edge.

Centralized Mapping

I used the University of Hawaii’s OSPF (Open Shortest Path First) network at its Advanced Network Computing Lab (ANCL) to host both boxes. On the most basic level, OSPF is a link-state protocol: Each OSPF-enabled router has complete knowledge of how the various subnetworks are connected. OSPF, like a friendly traffic cop, will provide a copy of the specific network map to anyone with the proper credentials. Getting information directly from the network’s routers, combined with the “entire map” property of OSPF, is what makes these devices work.

After configuring Route Explorer’s initial network via the LCD on the 2U appliance, the rest of the setup and admin tasks, such as user management, Ethernet interface configuration, and route database administration, are done via a Web interface. The administrative interface on the Route Explorer is intuitive and easy to use, but the downloadable VNC (Virtual Network Computing) end-user interface is not as polished.

Route Explorer is centrally managed, for the most part, and has three main modes of operation: network monitoring, route recording, and historical. In network monitoring mode, Route Explorer listens for changes and can be configured to send out alerts (syslog alert or SNMP trap). I found this to be a particularly useful feature, as it will alert administrators if the network routing topology changes.

In recording mode, the Route Explorer simply records to a database all the routes it hears on the wire. This allows statistical analysis of network routes during specific periods of time.