HP unveiled the Virus Throttle technology at an RSA Conference early last year. It has a lot in common with intrusion detection/prevention systems in that it monitors network behavior for things like abnormally high levels of connections. It then moves to contain virus attacks without waiting for a signature, and uses message queuing to throttle back the offending exploit without impacting normal traffic.

Jon Weatherall, UK country manager for the Roseville, California-based HP unit, said that until now, it has only been available on routed (Layer-3) traffic and applied to data flowing between VLANs, but not within them on switched (Layer-2) traffic. He said this gap has now been filled. Virus Throttle was only available in router-traffic mode, but now it can also be used on bridged traffic, he said.

The 3500 and 5400 series are two sides of a single family. The big difference is in form factor: while the 3500 is a 24- and 48-port stackable line, the 5400 is a 48- or 96-port chassis.