Scaling intrusion-prevention systems for 10G, 40G and beyond

While many IT security professionals regard intrusion-preventions systems to be a natural extension of intrusion-detection systems, an IPS is actually another type of access control mechanism, rather than simply a a sister to IDS.  In fact, it may surprise you to know that the term IPS is actually younger than IDS.  It  is a colloquial term first used by Andrew Plato, a technical consultant with a major IT security vendor that, way back in the late 1990s, developed the industry's first IDS platform.

In its purest form, an IPS makes a number of access control decisions based on the content of the application, rather than taking a traditional firewall approach of monitoring IP addresses, ports and other connective links.

Back in 1998 Plato opined that a good IPS should feature a sophisticated analytical engine, but one that generates as few false positives as possible.  Provided this is the case, he said at the time, then a good IPS has a number of advantages over IDS, since it can sit in line with an IP traffic flow and analyze the data stream in real time.

In addition, most modern IPS solutions also have the ability to analyze Layer 7 protocols such as FTP, HTTP and SMTP, and make decisions on whether to allow or quarantine the IP packets as required, even if the data is encrypted.

But are today's IPS platforms up to the task of scanning IP traffic at the high speeds needed in a modern IT environment?

The problem facing IT professionals is that, with the Internet growing at 40% to 60% a year (according to Atlas Internet Observatory), and against the backdrop of a mobile data explosion, it's important that IPS technology can keep up with this bandwidth growth and not become the bottleneck in the network.

It's also becoming clear that, on a typical network today, users are placing a very heavy load on each port of a multi-10G port system and, while there are IPS products available that are capable of supporting a multiple 10Gbps port topology, providing continuous 10Gbps throughput on these ports is a something of a challenge.

The most worrying part of this development is how IPS platforms can be scaled to meet the needs of 40G and 100G IPS technologies, which are set be introduced to the IT/network mix in the next few years.

Until a few years ago, it could be argued that IPS platforms were up to the task, especially since most adopted a core five-stage real-time analysis process that steps through a number of stages as various IT threats are encountered when monitoring data streams that flow both in and out of the IT resource.

The first stage is to bandwidth throttle any suspicious IP traffic to give the security software a chance to analyze the data stream -- say, an e-mail message stream -- and deal with suspect messages and/or attachments in real time.

If the data is found to be suspect, but does not conform to known infection signatures, then the second stage is for the message's header to be analyzed and, if an infection is found, the data can be quarantined.

The third stage involves performing user management and address validation, typically by applying a number of automated checks to verify whether the message comes from a source previously known to be dangerous.

The fourth stage involves applying an anti-malware and anti-hacking analysis engine for anything suspicious that has passed the first three analysis stages but does not pass muster.

The fifth stage typically involves using the analysis engine to weed out anything that still looks suspicious for later,  manual analysis by the IT security staff concerned.

However, the increasing sophistication of malware, together with the recursive and obfuscated coding approach taken by an increasingly criminal hacking fraternity -- and, of course, the higher network speeds seen on today's networking systems -- means that IPS systems are under pressure to keep up, both in terms of handling the amount of data, but also in having the raw horsepower to run more sophisticated algorithms.

So how serious is the threat of an intrusion?

A recent online poll carried out by Napatech found that a quarter of respondent firms have suffered a network intrusion. The interactive poll of more than 300 attendees at one of our online events found that 25% of respondents had experienced an intrusion incident, with 44% of these incidents occurring within the last 12 months.

The important thing to realize here is that network intrusion events are not just an irritation -- as they were back in the early days of IT networking -- they can also be commercially damaging.

This is because, unlike the altruistic 1980s, when hackers tended to be fellow engineers who also had access to the dial-up modems, expertise and other IT resources that were required to gain access to other businesses' online assets, the majority of attacks today are carried out by highly sophisticated criminal organizations attempting to steal data or hijack computing resources for their own illegal use.

These poll results were confirmed by a PricewaterhouseCooper-sponsored survey, details of which were announced at the recent Infosecurity Europe show in London. That survey showed that 83% of smaller organizations had experienced a security incident in the last year, compared with 45% two years earlier.

The PwC/Infosecurity survey also revealed that 90% of all organisations had increased their expenditure on IT security technology, while smaller businesses are now spending 10% of their IT budget on security issues compared to 7% two years ago.

The report attributes the rise partly on the increasing use of cloud computing and social networks within enterprises.

Delving into the study reveals that 15% of large companies noted IPS systems are under pressure to keep up, both in terms of handling the amount of data, but also in having the raw horsepower to run more sophisticated algorithms that their IT resources had been accessed by an unauthorized outsider in the last 12 months, and 25% had suffered a denial-of-service attack -- double the number logged in the last survey carried out two years earlier.

The report also found that the rate of adoption of newer technologies has accelerated over the last two years, with most respondents now using wireless networking, remote access and VoIP technologies.

In addition, the number of organizations allowing staff to have remote access to their systems has also increased with around 90% of large companies now offering this facility.

These figures confirm that our Napatech online poll is on track and that the number of intrusion incidents is definitely on the rise. This, in turn, is also forcing most organizations to increase the proportion of their IT budget that they spend on security technologies.

Raising the security game

Businesses are not just increasing their IT security budgets, they are also raising their game when it comes to security strategies.

Given this scenario, the key challenge now is scaling these systems to keep up with the increasing bandwidth generated by richer content in e-mails and on Web sites, more video and teleconferencing and the transition to cloud computing.

The important thing to realize is that all these innovative services provide a new and high-speed avenue of attack for hackers. And because of this, network security systems need to react in real-time to contain the problem.

To keep up with these high-speed, real-time demands, the traditional approach of network security appliance vendors has been to invest in the development of customized, proprietary hardware. However, a new approach is emerging where off-the-shelf standard PC server hardware is being used, negating the need for hardware development.

The Napatech poll revealed that the majority of network security appliances being used are still based on proprietary hardware, but for every three proprietary systems, there are now two systems based on standard PC server hardware.

In the past, PC servers have not been powerful enough to meet the demands of security applications like IPS, but the latest generation of PC servers provide significant processing power and the PC roadmap promises even better performance to come.

In fact, it is now more economical to build network security appliances based on standard PC server hardware.  But, one of the most compelling reasons to consider this approach is the ability to scale performance.

It has been demonstrated, for example, that an IPS system based on eight instances of a standard SNORT application running in parallel can support full-throughput 10Gbps. This technique takes advantage of the multiple CPU cores available in modern PC servers. As the number of cores increases and the power of each core ramps up, the ability to scale performance increases.

Indeed, it's worth noting that CPU chipmakers such as Intel and AMD are increasing the performance of their chips by as much as 50% every year.

Can the vendors of proprietary network security appliances keep up with this kind of performance roadmap? Does it even make sense to try?

Napatech is the leading OEM supplier of multi-port 10 GbE and 1 GbE intelligent adapters for real-time network analysis with over 60,000 Ethernet ports deployed. For more information visit us at:  A recording of a Napatech webinar on this subject can be found at: (registration required).


Copyright © 2010 IDG Communications, Inc.

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