Off-Site Control

Here and There

The NexVu Controller, a 1U, rackmount box that resides in your main office, collects information from the 2U, rackmount Manager boxes installed on each network you're monitoring. The Manager, a promiscuous network probe, monitors and analyzes LAN traffic.

The units have both Ethernet connections and internal modems for dial-up access. The modems also provide system access when the WAN link is down. And the Manager can act as terminal server, providing out-of-band access to itself. The Manager installation process is so simple you could talk an inexperienced staffer through the remote-office setup over the phone. Or you can preconfigure the Manager before sending it to your remote office.

Once the units were on the network, I accessed the Controller's internal Web page, which brought me to the NexVu Command Center--the management program for NexVu products. From there I could access help pages, perform account management and see stored management reports.

The Controller's Web page discovered that my PC wasn't running Java, so it walked me through installing the latest version. It then installed a desktop shortcut to point to the NexVu Command Center.Once Java was installed, I logged on to the Controller and completed the configuration by telling the Controller about the Manager and entering the Manager's IP address and registration code. At that point, the Controller and Manager were communicating.

I used only one Manager in my tests, but NexVu says there is no limit to the number of Managers a Controller can manage. The practical limitation depends on the number of system admins simultaneously using the Controller: The more people

hitting the unit, the slower it runs. Additionally, one Controller can oversee other Controllers, so you can set up hierarchies. The Controller cannot correlate flows from a machine under one Manager's purview to a machine under another Manager's purview, but NexVu says it expects to add that feature to the software's next release.

The Command Center program displays the Controller and Manager in a tree structure. Clicking on either led me to a screen with hierarchical tabs covering the configuration, reports, status and tools. Additionally, each tab had subtabs. It took me about half a day to get used to the tab motif--it is not terribly intuitive.

Packet CaptureI cut my IT teeth on packet analyzers, so I wanted to see what the Manager and Controller combo could

do. The Manager offers a complete packet-capture program that shows info on protocols in use. NexVu says the product can decode more than 800 protocols and 3,700 applications. Among the supported protocols are those for Oracle, SAP and KaZaa.

The wizard for building a packet-capture filter is straightforward, but the functions are too simple. I could filter traffic based on traffic source, destination or both. I could choose protocol type, packet length, and broadcast or multicast packets. Further, I could set rules to refine the captured traffic. The rules are connected with a selectable global meta-rule that lets you decide how data will be captured: if any rule's condition is met, if all rules' conditions are met, if any rule's conditions are not met, or if no rule's conditions are met. The product does not let you define multiple filter rule sets or capture traffic based on data content. In comparison, WildPackets' EtherPeek and Network Associates Sniffer's offer more flexible rule sets.

Overall, Manager's packet-capture capabilities aren't as feature-rich or easy to use as those offered by Sniffer and EtherPeek, but they are more than adequate for most network troubleshooting. They're available where you need them, when you need them. And they're designed so the captured data is not sent over your WAN; instead only screen updates are sent, helping to preserve bandwidth and maintain security.

Network Status

Both the Controller and Manager have status screens displaying a high-level view of the network. The Controller's status screen has an information box for each Manager that contains simple bar graphs, strip charts or pie charts. The graphs or charts display the amount of traffic passing through each node by protocol and the percentage of maximum load the line is carrying. Under the graphs, you'll see the number of active flows, the number of bytes per second flowing on that Manager's network, and the packets per second on the network for each Manager.

Moving your mouse over a graph brings up labels that explain which graph segment correlates to which protocol. You can get to the Manager from the Controller to glean more detail with two mouse clicks. However, this is an error-prone operation in larger networks. The ability to go directly from the Controller status screen to the Manager status screen by clicking on any chart that catches your eye has been promised in the July software release.

You can set the Manager to run up to 19 monitoring programs to watch various aspects of network performance and then report exceptions to the Controller. You also can

configure the Manager to run network-performance reports on a user-selected schedule and send them to the Controller. Reports also can be run on command. NexVu says the Manager stores about a month's worth of data for a typical site, so the network manager can get a good idea of trends and abnormal traffic.

In the beta version I tested, some reports on the menu wouldn't run; I couldn't get the backup or checkpoint software to work; it wasn't obvious how to access reports that had been run by the scheduler; and root-cause analysis wasn't available. NexVu says these problems should be cleared up in the main release.Mike Avery is the founder of Gunnison Territory Network Consultants. Write to him at [email protected].

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