Network remediation comes of age

Robert Heinlein once said that the world's greatest swordsman is not afraid of the second-greatest swordsman, but rather of the amateur, who will do the unexpected. Currently, most of our networks are well protected from the expected attacks. But Arbor Networks' Peakflow X 3.1 is intended to detect and repel the unexpected ones.

Peakflow X comes as two appliances, a Collector and a Controller. An Arbor Networks engineer typically installs these devices for new customers, so we invited the engineer to install them on our network. Peakflow X runs on ArbOS, an Arbor Networks implementation of the OpenBSD operating system.

The manual is clear enough that you could get away with installing it yourself. Knowledge of Unix helps, but is not required.

We then gave our Web browser the IP address of the Peakflow X Controller, which got us to the management console. When the screen came up, we realized we had to turn off our anti-popup software. Remember to use HTTPS so that communications with the Controller are secure.

Be sure the engineer shows you how to start using the console. In our hubris, we shooed him out the door too early, then sat down at the console and proceeded to do everything wrong. But the "Initial Setup and Execution" chapter in the user manual got us back on track.

The management console interface is easy to use, but that does not mean it is always intuitive. We give Peakflow X high scores for ease of use because of the first-class manual and the consistent interface on the console screens.

We placed the appliances inside our firewall to monitor traffic. In enterprise deployments, multiple Collectors will be located throughout the network to capture data flows and forward them to the Controller. One Collector can monitor traffic through 10 core switches.

We began by attacking the Controller to test that the security product could protect itself.

All network-based anomaly-detection products are hardened, but Peakflow X did better than most. It would not return our pings and although our clever Nessus program identified Peakflow X's few open ports, Nessus did not identify the product and could only guess that it was an OpenBSD computer.

Although it is not advertised as such, Peakflow X normally is completely stealthy, although an active auto discovery tool is available, and it watches the network passively. The manual recommends allowing it a week to learn all the hosts and their traffic flows.

We used different methods to generate abnormal network traffic. The most interesting was our use of a vulnerability scanner in attack mode. Instead of our trusty Linux-based Nessus scanner, we used the new Tenable NeWT Security Scanner (www.tenablesecurity.com/products/newt.shtml).

NeWT has two advantages: It can run on Microsoft Windows, and it places a handy user interface around the solid Nessus scanning engine. Peakflow then displayed the abnormal traffic in a colorful graph.

The management interface has seven tabbed sections. We spent most of our time in the Map section, grouping and regrouping our equipment on a logical graphic display of the network. Real-world networks tend to change as organizations reorganize so you may want to start by accepting the groups that Peakflow X will create for you based on like behavior.

We also monitored the Events tab, checking violations and warnings, while the Investigate tab allowed us to delve into unusual traffic flows.

Likes and dislikes

Version 3.1 has two new features, Safe Quarantine and Worm Vaccine. When Peakflow X detects worm-like activity it can send commands to Cisco Systems' Catalyst 6500 Series switches and Check Point Software Technologies firewalls to suppress the offending traffic. We liked that the worm can be stopped inside the network and not only at the perimeter. Worm Vaccine will block specific ports and protocols, preventing the worm from propagating.

Reporting has improved from previous versions, and the network performance data can be gleaned from a historic usage database.

We also appreciated Peakflow X's ability to monitor dark address space — unused IP addresses that should not show traffic.

We would suggest improving Peakflow X by providing a quick-start card to save time for impatient administrators. The manual could also use an index. And we missed having the application-level data we had become accustomed to when using Q1 Labs QRadar.

The bottom line

Although Peakflow X is priced at the high end of network-based anomaly-detection products, we feel that the traffic flow analysis features and damage mitigation capabilities make it worthwhile. When a fast-spreading worm is loose, Peakflow X has the potential to react quickly enough to harden the network before significant damage is done, allowing the network to continue operations throughout the worm event, and that justifies its cost.

Greer is a network security consultant. He can be reached at egreer@thecourageequation.com.