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Scalable NetFlow – 3 Key Questions to Ask Your NetFlow Vendor

Why is flows per second a flawed way to measure a netflow collector’s capability?

Flows-per-second is often considered the primary yardstick to measure the capability of a netflow analyzers flow capture (aka collection) rate.

This seems simple on its face. The more flows-per-second that a flow collector can consume, the more visibility it provides, right? Well, yes and no.

The Basics

NetFlow was originally conceived as a means to provide network professionals the data to make sense of the traffic on their network without having to resort to expensive per segment based packet sniffing tools.

A flow record contains at minimum the basic information pertaining to a transfer of data through a router, switch, firewall, packet tap or other network gateway. A typical flow record will contain at minimum: Source IP, Destination IP, Source Port, Destination Port, Protocol, Tos, Ingress Interface and Egress Interface. Flow records are exported to a flow collector where they are ingested and information orientated to the engineers purposes are displayed.

Measurement

Measurement has always been how the IT industry expresses power and competency. However, a formula used to reflect power and ability changes when a technology design undergoes a paradigm shift.

For example, when expressing how fast a computer is we used to measure the CPU clock speed. We believed that the higher the clock speed the more powerful the computer. However, when multi-core chips were introduced the CPU power and speed dropped but the CPU in fact became more powerful. The primary clock speed measurement indicator became secondary to the ability to multi-thread.

The flows-per-second yardstick is misleading as it incorrectly reflects the actual power and capability of a flow collector to capture and process flow data and it has become prone to marketing exaggeration.

Flow Capture Rate

Flow capture rate ability is difficult to measure and to quantify a products scalability. There are various factors that can dramatically impact the ability to collect flows and to retain sufficient flows to perform higher-end diagnostics.

Its important to look not just at flows-per-second but at the granularity retained per minute (flow retention rate), the speed and flexibility of alerting, reporting, forensic depth and diagnostics and the scalability when impacted by high-flow-variance, sudden-bursts, number of devices and interfaces, the speed of reporting over time, the ability to retain short-term and historical collections and the confluence of these factors as it pertains to scalability of the software as a whole.

Scalable NetFlow and flow retention rates are particularly critical to determine as appropriate granularity is needed to deliver the visibility required to perform Anomaly Detection, Network Forensics, Root Cause Analysis, Billing substantiation, Peering Analysis and Data retention compliance.

The higher the flows-per-second and the flow-variance the more challenging it becomes to achieve a high flow-retention-rate to archive and retain flow records in a data warehouse.

A vendors capability statement might reflect a high flows-per-second consumption ability but many flow software tools have retention rate limitations by design.

It can mean that irrespective of achieving a high flow collection rate the netflow analyzer might only be capable of physically archiving 500 flows per minute. Furthermore, these flows are usually the result of sorting the flow data by top bytes to identify Top 10bandwidth abusers. Netflow products of this kind can be easily identified because they often tend to offer benefits orientated primarily to identifying bandwidth abuse or network performance monitoring.

Identifying bandwidth abusers is of course a very important benefit of a netflow analyzer. However, it has a marginal benefit today where a large amount of the abuse and risk is caused by many small flows.

These small flows usually fall beneath the radar screen of many netflow analysis products.  Many abuses like DDoS, p2p, botnets and hacker or insider data exfiltration continue to occur and can at minimum impact the networking equipment and user experience. Lack of ability to quantify and understand small flows creates great risk leaving organizations exposed.

Scalability

This inability to scale in short-term or historical analysis severely impacts a flow monitoring products ability to collect and retain critical information required in todays world where copious data has created severe network blind spots.

To qualify if a tool is really suitable for the purpose, you need to know more about the flows-per-second collection formula being provided by the vendor and some deeper investigation should be carried out to qualify the claims.

 

With this in mind here are 3 key questions to ask your NetFlow vendor to understand what their collection scalability claims really mean:

  1. How many flows can be collected per second?

  • Qualify if the flows per second rate provided is a burst rate or a sustained rate.
  • Ask how the collection and retention rates might be affected if the flows have high-flow variance (e.g. a DDoS attack).
  • How is the collection, archiving and reporting impacted when flow variance is increased by adding many devices and interfaces and distinct IPv4/IPv6 conversations and test what degradation in speed can you expect after it has been recording for some time.
  • Ask how the collection and retention rates might change if adding additional fields or measurements to the flow template (e.g. MPLS, MAC Address, URL, Latency)
  • How many flow records can be retained per minute?

  • Ask how the actual number of records inserted into the data warehouse per minute can be verified for short-term and historical collection.
  • Ask what happens to the flows that were not retained.
  • Ask what the flow retention logic is. (e.g. Top Bytes, First N)
  • What information granularity is retained for both short-term and historically?
    • Does the datas time granularity degrade as the data ages e.g. 1 day data retained per minute, 2 days retained per hour 5 days retained per quarter
    • Can you control the granularity and if so for how long?

 

Remember – Rate of collection does not translate to information retention.

Do you know whats really stored in the software’s database? After all you can only analyze what has been retained (either in memory or on disk) and it is that information retention granularity that provides a flow products benefits.

8 Keys to Understanding NetFlow for Network Security, Performance & Overall IT Health

NetFlow for Usage-Based Billing and Peering Analysis

Usagebased billing refers to the methods of calculating and passing back the costs of running a network to the consumers of data that occur through the network. Both Internet Service Providers (ISP) and Corporations have a need for Usage-based billing with different billing models.

NetFlow is the ideal technology for usage-based billing because it allows for the capture of all transactional information pertaining to the usage and some smart NetFlow technologies already exist to assist in the counting, allocation, and substantiation of data usage.

Advances in telecommunication technology have enabled ISPs to offer more convenient, streamlined billing options to customers based on bandwidth usage.

One billing model used most commonly by ISPs in the USA is known as the 95th percentile. The ISP filters the samples and disregards the highest 5% in order to establish the bill amount. This is an advantage to data consumers who have bursts of traffic because they’re not financially penalized for exceeding a traffic threshold for brief periods of time. The solution measures traffic employing a five-minute granularity standard typically over the course of a month.

The disadvantage of the 95th percentile model is that its not sustainable business model as data continues to become a utility like electricity.

A second approach is a utility-based metered billing model that involves retaining a tally of all bytes consumed by a customer with some knowledge of data path to allow for premium or free traffic plans.

Metered Internet usage is used in countries like Australia and most recently Canada who have nationally moved away from a 95th percentile model. This approach is also very popular in corporations whose business units share common network infrastructure and who are unwilling to accept “per user” cost, but rather a real consumption-based cost.

Benefits of usage-based billing are:

  • Improved transparency about the cost of services;
  • Costs feedback to the originator;
  • Raised cost sensitivity;
  • Good basis for active cost management;
  • The basis for Internal and external benchmarking;
  • Clear substantiation to increase bandwidth costs;
  • Shared infrastructure costs can also be based on consumption;
  • Network performance improvements.

For corporations, usage-based billing enables the IT department to become a shared service and viewed as a profit center rather than a cost center. It can become viewed as something that’s a benefit and a catalyst for business growth rather than a necessary but expensive line item in the budget.

For ISPs in the USA, there is no doubt that utility-based costs per byte model will continually be contentious as video and TV over Internet usage increases. In other regions, new business models that include packaging of video over “free zones” services have become popular meaning that the cost of premium content provision has fallen onto the content provider making utility billing viable in the USA.

NetFlow tools can include methods for building billing reports and offer a variety of usage-based billing model calculations.

Some NetFlow tools even include an API to allow the chart-of-accounts to be retained and driven from traditional accounting systems using the NetFlow system to focus on the tallying. Grouping algorithms should be flexible within the solution to allow for grouping of all different variables such as interfaces, applications, Quality of Service (QoS), MAC Addresses, MPLS, and IP groups. For ISPs and large corporations Asynchronous Network Numbers (ASN) also allow for analysis of data-paths allowing sensible negotiations with Peering partners and Content partners.

Look out for more discussion on peering in an upcoming blog…

Performance Monitoring & Security Forensics: The 1-2 Punch for Network and IT Infrastructure Visibility

How to Improve Cyber Security with Advanced Netflow Network Forensics

Most organizations today deploy network security tools that are built to perform limited prevention – traditionally “blocking and tackling” at the edge of a network using a firewall or by installing security software on every system.

This is only one third of a security solution, and has become the least effective measure.

The growing complexity of the IT infrastructure is the major challenge faced by existing network security tools. The major forces impacting current network security tools are the rising level of sophistication of cybercrimes, growing compliance and regulatory mandates, expanding virtualization of servers and the constant need for visibility compounded by ever-increasing data volumes. Larger networks involve enormous amounts of data, into which the incident teams must have a high degree of visibility for analysis and reporting purposes.

An organization’s network and security teams are faced with increasing complexities, including network convergence, increased data and flow volumes, intensifying security threats, government compliance issues, rising costs and network performance demands.

With network visibility and traceability also top priorities, companies must look to security network forensics to gain insight and uncover issues. The speed with which an organization can identify, diagnose, analyze, and respond to an incident will limit the damage and lower the cost of recovery.

Analysts are better positioned to mitigate risk to the network and its data through security focused network forensics applied at the granular level. Only with sufficient granularity and historic visibility and tools that are able to machine learn from the network Big Data can the risk of an anomaly be properly diagnosed and mitigated.

Doing so helps staff identify breaches that occur in real-time, as well as Insider threats and data leaks that take place over a prolonged period. Insider threats are one of the most difficult to detect and are missed by most security tools.

Many network and security professionals assume that they can simply analyze data captured using their standard security devices like firewalls and intrusion detection systems, however they quickly discover limitations as these devices are not designed for and cannot record and report on every transaction due to lack of deep visibility, scalability and historic data retention making old fashioned network forensic reporting expensive and impractical.

NetFlow is an analytics software technology that enables IT departments to accurately audit network data and host-level activity. It enhances network security and performance making it easy to identify suspicious user behaviors to protect your entire infrastructure.

A well-designed NetFlow forensic tool should include powerful features that can allow for:

  • Micro-level data recording to assist in identification of real-time breaches and data leaks;
  • Event notifications and alerts for network administrators when irregular traffic movements are detected;
  • Tools that highlight trends and baselines, so IT staff can provision services accordingly;
  • Tools that learn normal behavior, so Network Security staff can quickly detect and mitigate threats;
  • Capture highly granular traffic over time to enable deep visibility across the entire network infrastructure;
  • 24-7 automation, flexible reporting processes to deliver usable business intelligence and security forensics specifically for those analytics that can take a long time to produce.

Forensic analysts require both high-level and detailed visibility through aggregating, division and drilldown algorithms such as:

  • Deviation / Outlier analysis
  • Bi-directional analysis
  • Cross section analysis
  • Top X/Y analysis
  • Dissemination analysis
  • Custom Group analysis
  • Baselining analysis
  • Percentile analysis
  • QoS analysis
  • Packet Size analysis
  • Count analysis
  • Latency and RTT analysis

Further when integrated with a visual analytics process it will enable additional insights to the forensic professional when analyzing subsets of the flow data surrounding an event.

In some ways it needs to act as a log analyzer, security information and event management (SIEM) and a network behavior anomaly and threat detector all rolled into one.

The ultimate goal is to deploy a multi-faceted flow-analytics solution that can compliment your business by providing extreme visibility and eliminating network blindspots, both in your physical infrastructure and in the cloud, automatically detecting and diagnosing your entire network for anomalous traffic and improving your mean time to detect and repair.

Performance Monitoring & Security Forensics: The 1-2 Punch for Network and IT Infrastructure Visibility

5 Perks of Network Performance Management

Network performance management is something that virtually every business needs, but not something that every business is actively doing, or even aware of.  And why should they?

While understanding the technical side of things is best left to the IT department, understanding the benefits of a properly managed network is something that will help get the business managers on board, especially when good performance management solutions might be a cost that hadn’t been considered.  So what are the benefits?

1.  Avoiding downtime – Downtime across an entire network is going to be rare, but downtime in small areas of the network are possible if it gets overloaded.  Downtime of any kind is just not something that business can tolerate, for a few reasons:

  • it leaves that area of the network unmonitored, which is a serious security issue
  • shared files won’t be accessible, nor will they be updating as users save the files.  This will lead to multiple versions of the same file, and quite a few headaches when the network is accessible again
  • downtime that affects customers is even worse, and can result in lost revenue or negative customer experiences

2.  Network speed – This is one of the most important and easily quantified aspects of managing netflow.  It will affect every user on the network constantly, and anything that slows down users means either more work hours or delays.  Obviously, neither of these is a good problem to have.  Whether it’s uploading a file, sending a file to a coworker, or sending a file to a client; speed is of paramount importance.

3.  Scalability – Almost every business wants to grow, and nowhere is that more true than the tech sector.  As the business grows, the network will have to grow with it to support more employees and clients.  By managing the performance of the network, it is very easy to see when or where it is being stretched too thin or overwhelmed.  As performance degrades, it’s very easy to set thresholds that show when the network need upgraded or enlarged.

4.  Security – Arguably the most important aspect of network management, even though it might not be thought of as a performance aspect.  An unsecured network is worse than a useless network, and data breaches can ruin a company.  So how does this play into performance management?

By monitoring netflow performance, it’s easy to see where the most resources are being used.  Many security attacks drain resources, so if there are resource spikes in unusual areas it can point to a security flaw.  With proper software, these issues can be not only monitored, but also recorded and corrected.

5.  Usability – Unfortunately, not all employees have a working knowledge of how networks operate.  In fact, as many in IT support will attest, most employees aren’t tech savvy.  However, most employees will need to use the network as part of their daily work.  This conflict is why usability is so important.  The easiest way to minimize training costs with any network management program is to ensure that it is as user-friendly as possible.

The fanciest, most impressive network performance management system isn’t worth anything if no one knows how to use and optimize it properly.  Even if the IT department has no issues with it, the reports and general information should be as easy to decipher as possible.

Is your network as optimized as it could be?  Are you able to monitor the network’s performance and flow,  or do network forensics to determine where issues are?  Don’t try to tackle all of this on your own, contact us and let us help you support your business with the best network monitoring for your specific needs.

8 Keys to Understanding NetFlow for Network Security, Performance & Overall IT Health

5 Benefits of NetFlow Performance Monitoring

NetFlow can provide the visibility that reduces the risks to business continuity associated with poor performance, downtime and security threats. As organizations continue to rely more and more on computing power to run their business, transparency of business applications across the network and interactions with external systems and users is critical and NetFlow monitoring simplifies detection, diagnosis, and resolution of network issues.

Traditional SNMP tools are too limited in their collection capability and the data extracted is very coarse and does not provide sufficient visibility. Packet capture tools can extract high granularity from network traffic but are dedicated to a port mirror or a per segment capture and are built for specialized short term captures rather than long historical analyses as well as packet based Predictive AI Baselining analytics tools traditionally do not provide the ability to perform forensic analysis of various sub-sections or aggregated views and therefore also suffer from a lack of visibility and context.

By analyzing NetFlow data, a network engineer can discover the root cause of congestion and find out the users, applications and protocols that are causing interfaces to exceed utilization. They can determine the Type or Class of Service (QoS) and group with application mapping such as Network Based Application Recognition (NBAR) to identify the type of traffic such as when peer-to-peer traffic tries to hide itself by using web services and so on.

NetFlow allows granular and accurate traffic measurements as well as high-level aggregated traffic collection that can assist in identifying excessive bandwidth utilization or unexpected application traffic. NetFlow enables networks to perform IP traffic flow analyses without deploying external probes, making traffic Predictive AI Baselining analytics cheap to deploy even on large network environments.

Understanding the benefits of a properly managed network might be a cost that hasn’t been considered by business managers.  So what are the benefits of NetFlow performance monitoring?

Avoiding Downtime

Service outages can cause simple frustrations such as issues when saving opened files to a suddenly inaccessible server or cause delays to business process can impact revenue. Downtime that affects customers can result in negative customer experiences and lost revenue.

Network Speed

Slow network links cause severe user frustration that impacts productivity and causes delays.

Scalability

As the business grows, the network needs to grow with it to support more computing processes, employees and clients. As performance degrades, it can be easy to set thresholds that show when, where and why the network is exceeding it’s capability. By having historical performance of the network, it is very easy to see when or where it is being stretched too thin or overwhelmed and to easily substantiate upgrades.

Security

Security Predictive AI Baselining analytics is arguably the most important aspect of network management, even though it might not be thought of as a performance aspect. By monitoring NetFlow performance, it’s easy to see where the most resources are being used. Many security attacks drain resources, so if there are resource spikes in unusual areas it can point to a security flaw. With advanced NetFlow diagnostics software, these issues can be not only monitored, but also recorded and corrected.

Peering

NetFlow Predictive AI Baselining analytics allows organizations to embrace progressive IT trends to analyze peering paths, or virtualized paths such as Multiprotocol Label Switching (MPLS), Virtual Local Area Networks (VLAN), make use of IPv6, Next Hops, BGP, MAC Addresses or link internal IP’s to Network Address Translated (NAT) IP addresses.

MPLS creates new challenges when it comes to network performance monitoring and security with MPLS as communication can occur directly without passing through an Intrusion Detection System (IDS). Organizations have two options to address the issue: Implement a sensor or probe at each site, which is costly and fraught with management hassles; or turn on NetFlow at each MPLS site and send MPLS flows to a NetFlow collector that becomes a very cost-effective option because it can make use of existing network infrastructure.

With NetFlow, network performance issues are easily resolved because engineers are given in-depth visibility that enables troubleshooting – all the way down the network to a specific user. The solution starts by presenting the interfaces being used.

An IT engineer can click on the interfaces to determine the root cause of a usage spike, as well as the actual conversation and host pairs that are dominating bandwidth and the associated user information. Then, all it takes is a quick phone call to the end-user, instructing them to shut down resource-hogging activities, as they’re impairing network performance.

IT departments are tasked with responding to end-user complaints, which often relate to network sluggishness. However, many times an end-user’s experience has more to do with an application or server failing to respond within the expected time period that can point to a Latency, Quality of Service (QoS) or server issue. Traffic Latency can be analyzed if supported in the NetFlow version. Statistics such as Round Trip Time (RTT) and Server Response Time (SRT) can be diagnosed to identify whether a network problem is due to an application or service experiencing slow response times.

Baselines of RTT and SRT can be learned to determine whether response time is consistent or is spiking over a time period. By observing the Latency over time alarms can be generated when Latency increases above the normal threshold.

TCP Congestion flags can also serve as an early warning system where Latency is unavailable.

NetFlow application performance monitoring provides the context around an event or anomaly within a host to quickly identify the root cause of issues and improve Mean Time To Know (MTTK) and Mean Time To Repair (MTTR).

Performance Monitoring & Security Forensics: The 1-2 Punch for Network and IT Infrastructure Visibility

What is NetFlow & How Can Organizations Leverage It?

NetFlow is a feature originally introduced on Cisco devices (but now generally available on many vendor devices) which provides the ability for an organization to monitor and collect IP network traffic entering or exiting an interface.
Through analysis of the data provided by NetFlow, a network administrator is able to detect things such as the source and destination of traffic, class of service, and the causes of congestion on the network.

NetFlow is designed to be utilized either from the software built into a router/switch or from external probes.

The purpose of NetFlow is to provide an organization with information about network traffic flow, both into and out of the device, by analyzing the first packet of a flow and using that packet as the standard for the rest of the flow. It has two variants which are designed to allow for more flexibility when it comes to implementing NetFlow on a network.

NetFlow was originally developed by Cisco around 1990 as a packet switching technology for Cisco routers and implemented in IOS 11.x.

The concept was that instead of having to inspect each packet in a “flow”, the device need only to inspect the first packet and create a “NetFlow switching record” or alternatively named “route cache record”.

After that that record was created, further packets in the same flow would not need to be inspected; they could just be forwarded based on the determination from the first packet. While this idea was forward thinking, it had many drawbacks which made it unsuitable for larger internet backbone routers.

In the end, Cisco abandoned that form of traffic routing in favor of “Cisco Express Forwarding”.

However, Cisco (and others) realized that by collecting and storing / forwarding that “flow data” they could offer insight into the traffic that was traversing the device interfaces.

At the time, the only way to see any information about what IP addresses or application ports were “inside” the traffic was to deploy packet sniffing systems which would sit inline (or connected to SPAN/Mirror) ports and “sniff” the traffic.  This can be an expensive and sometimes difficult solution to deploy.

Instead, by exporting the NetFlow data to an application which could store / process / display the information, network managers could now see many of the key meta-data aspects of traffic without having to deploy the “sniffer” probes.

Routers and switches which are NetFlow-capable are able to collect the IP traffic statistics at all interfaces on which NetFlow is enabled. This information is then exported as NetFlow records to a NetFlow collector, which is typically a server doing the traffic analysis.

There are two main NetFlow variants: Security Event Logging and Standalone Probe-Based Monitoring.

Security Event Logging was introduced on the Cisco ASA 5580 products and utilizes NetFlow v9 fields and templates. It delivers security telemetry in high performance environments and offers the same level of detail in logged events as syslog.

Standalone Probe-Based Monitoring is an alternative to flow collection from routers and switches and uses NetFlow probes, allowing NetFlow to overcome some of the limitations of router-based monitoring. Dedicated probes allow for easier implementation of NetFlow monitoring, but probes must be placed at each link to be observed and probes will not report separate input and output as a router will.

An organization or company may implement NetFlow by utilizing a NetFlow-capable device. However, they may wish to use one of the variants for a more flexible experience.

By using NetFlow, an organization will have insight into the traffic on its network, which may be used to find sources of congestion and improve network traffic flow so that the network is utilized to its full capability.

8 Keys to Understanding NetFlow for Network Security, Performance & Overall IT Health

Seven Reasons To Analyze Network Traffic With NetFlow

NetFlow allows you to keep an eye on traffic and transactions that occur on your network. NetFlow can detect unusual traffic, a request for a malicious destination or a download of a larger file. NetFlow analysis helps you see what users are doing, gives you an idea of how your bandwidth is used and can help you improve your network besides protecting you from a number of attacks.

There are many reasons to analyze network traffic with NetFlow, including making your system more efficient as well as keeping it safe. Here are some of the reasons behind many organizations  adoption of NetFlow analysis:

  • Analyze all your network NetFlow allows you to keep track of all the connections occurring on your network, including the ones hidden by a rootkit. You can review all the ports and external hosts an IP address connected to within a specific period of time. You can also collect data to get an overview of how your network is used.

 

  • Track bandwidth use. You can use NetFlow to track bandwidth use and see reports on the average use of This can help you determine when spikes are likely to occur so that you can plan accordingly. Tracking bandwidth allows you to better understand traffic patterns and this information can be used to identify any unusual traffic patterns. You can also easily identify unusual surges caused by a user downloading a large file or by a DDoS attack.

 

  • Keep your network safe from DDoS attacks. These attacks target your network by overloading your servers with more traffic than they can handle. NetFlow can detect this type of unusual surge in traffic as well as identify the botnet that is controlling the attack and the infected computers following the botnet’s order and sending traffic to your network. You can easily block the botnet and the network of infected computers to prevent future attacks besides stopping the attack in progress.

 

  • Protect your network from malware. Even the safest network can still be exposed to malware via users connecting from home or via people bringing their mobile device to work. A bot present on a home computer or on a Smartphone could access your network but NetFlow will detect this type of abnormal traffic and with auto-mitigation tools automatically block it.
  • Optimize your cloud. By tracking bandwidth use, NetFlow can show you which applications slow down your cloud and give you an overview of how your cloud is used. You can also track performances to optimize your cloud and make sure your cloud service provider is offering a cloud solution that corresponds to what they advertised.
  • Monitor users. Everyone brings their own Smartphone to work nowadays and might use it for purposes other than work. Company data may be accessible by insiders who have legitimate access but have an inappropriate agenda downloading and sharing sensitive data with outside sources. You can keep track of how much bandwidth is used for data leakage or personal activities, such as using Facebook during work hours.
  • Data Retention Compliance. NetFlow can fill in the gaps where other technologies cannot deliver. A well-architected NetFlow solution can help business and service providers to achieve and maintain data retention compliance for a wide range of government and industry regulations.

NetFlow is an easy way to monitor your network and provides you with several advantages, including making your network safer and collecting the data you need to optimize it. Having access to a comprehensive overview of your network from a single pane of glass makes monitoring your network easy and enables you to check what is going on with your network with a simple glance.

CySight solutions takes the extra step to make life far easier for the network and security professional with smart alerts, actionable network intelligence, scalability and automated diagnostics and mitigation for a complete technology package.

CySight can provide you with the right tools to analyze traffic, monitor your network, protect it and optimize it. Contact us  to learn more about NetFlow and how you can get the most out of this amazing tool.

8 Keys to Understanding NetFlow for Network Security, Performance & Overall IT Health

3 Ways Anomaly Detection Enhances Network Monitoring

With the increasing abstraction of IT services beyond the traditional server room computing environments have evolved to be more efficient and also far more complex. Virtualization, mobile device technology, hosted infrastructure, Internet ubiquity and a host of other technologies are redefining the IT landscape.

From a cybersecurity standpoint, the question is how to best to manage the growing complexity of environments and changes in network behavior with every introduction of new technology.

In this blog, we’ll take a look at how anomaly detection-based systems are adding an invaluable weapon to Security Analysts’ arsenal in the battle against known – and unknown – security risks that threaten the stability of today’s complex enterprise environments.

Put your network traffic behavior into perspective

By continually analyzing traffic patterns at various intersections and time frames, performance and security baselines can be established, against which potential malicious activity is monitored and managed. But with large swathes of data traversing the average enterprise environment at any given moment, detecting abnormal network behavior can be difficult.

Through filtering techniques and algorithms based on live and historical data analysis, anomaly detection systems are capable of detecting even the most subtly crafted malicious software that may pose as normal network behavior. Also, anomaly-based systems employ machine-learning capabilities to learn about new traffic as it is introduced and provide greater context to how data traverses the wire, thus increasing its ability to identify security threats as they are introduced.

Netflow is a popular tool used in the collection of network traffic for building accurate performance and cybersecurity baselines with which to establish normal network activity patterns from potentially alarming network behavior.

Anomaly detection places Security Analysts on the front foot

An anomaly is defined as an action or event that is outside of the norm. But when a definition of what is normal is absent, loopholes can easily be exploited. This is often the case with signature-based detection systems that rely on a database of pre-determined virus signatures that are based on known threats. In the event of a new and yet unknown security threat, signature-based systems are only as effective as their ability to respond to, analyze and neutralize such new threats.

Since signatures do work well against known attacks, they are by no means paralyzed against defending your network. Signature-based systems lack the flexibility of anomaly-based systems in the sense that they are incapable of detecting new threats. This is one of the reasons signature-based systems are typically complemented by some iteration of a flow based anomaly detection system.

Anomaly based systems are designed to grow alongside your network

The chief strength behind anomaly detection systems is that they allow Network Operation Centers (NOCs) to adapt their security apparatus according to the demands of the day. With threats growing in number and sophistication, detection systems that can discover, learn about and provide preventative methodologies  are the ideal tools with which to combat the cybersecurity threats of tomorrow. NetFlow Anomaly detection with automated diagnostics does exactly this by employing machine learning techniques to network threat detection and in so doing, automating much of the detection aspect of security management while allowing Security Analysts to focus on the prevention aspect in their ongoing endeavors to secure their information and technological investments.

8 Keys to Understanding NetFlow for Network Security, Performance & Overall IT Health

3 Key Differences Between NetFlow and Packet Capture Performance Monitoring

The increasing density, complexity and expanse of modern networking environments have fueled the ongoing debate around which network analysis and monitoring tools serve the needs of the modern engineer best – placing Packet Capture and NetFlow Analysis at center-stage of the conversation. Granted, both can be extremely valuable tools in ongoing efforts to maintain and optimize complex environments, but as an engineer, I tend to focus on solutions that give me the insights I need without too much cost on my resources, while complementing my team’s ability to maintain and optimize the environments we support.

So with this in mind, let’s take a look at how NetFlow, in the context of the highly-dense networks we find today, delivers three key requirements network teams rely on for reliable end-to-end performance monitoring of their environments.

A NetFlow deployment won’t drain your resources

Packet Capture, however rich in network metrics, requires sniffing devices and agents throughout the network, which invariably require some level of maintenance during their lifespan. In addition, the amount of space required to store and analyze packet data makes it an inefficient an inelegant method of monitoring or forensic analysis. Combine this with the levels of complexity networks can reach today, and overall cost and maintenance associated with packet sniffers can quickly become unfeasible. In the case of NetFlow, its wide vendor support across virtually the entire networking landscape makes almost every switch, router or firewall a NetFlow “ready” device. Devices’ built-in readiness to capture and export data-rich metrics makes it easy for engineers to deploy and utilize . Also, thanks to its popularity, NetFlow analyzers of varying feature-sets are available for network operations center (NOC) teams to gain full advantage of data-rich packet flows.

Striking the balance between detail and context

Considering how network-dependent and widespread applications have become in recent years, NetFlow’s ability to provide WAN-wide metrics in near real-time makes it a  suitable troubleshooting companion for engineers.   And with version 9 of NetFlow extending the wealth of information it collects via a template-based collection scheme, it strikes the balance between detail and high-level insight without placing too much demand on networking hardware – which is something that can’t be said for Packet Capture. Packet Capture tools, however, do what they do best, which is Deep Packet Inspection (DPI), which allows for the identification of aspects in the traffic hidden in the past to Netflow analyzers. But Netflow’s constant evolution alongside the networking landscape is seeing it used as a complement to solutions such as Cisco’s NBAR and other DPI solutions who have recognized that all they need to do is use flexible Netflow tools to reveal details at the packet level.

NetFlow places your environment in greater context

Context is a chief area where NetFlow beats out Packet Capture since it allows engineers to quickly locate root causes relating to performance by providing a more situational view of the environment, its data-flows, bottleneck-prone segments, application behavior, device sessions and so on. We could argue that packet sniffing is able to provide much of this information too, but it doesn’t give engineers the broader context around the information it presents, thus hamstringing IT teams from detecting performance anomalies that could be subscribed to a number of factors such as untimely system-wide application or operating system updates or a cross-link backup application pulling loads of data across the WAN during operational hours.

So does NetFlow make Packet Capture obsolete?

The short answer is, no. In fact, Packet Capture, when properly coupled with NetFlow, can make a very elegant solution. For example, using NetFlow to identify an attack profile or illicit traffic and then analyzing corresponding raw packets becomes an attractive solution. However, NetFlow strikes that perfect balance between detail and context and gives NOCs intelligent insights that reveals broader factors that can influence your network’s ability to perform. Gartner’s assertion that a balance of 80% NetFlow monitoring  coupled with 20% Packet Capture as the perfect combination of performance monitoring attests to NetFlow’s growing prominence as the monitoring tool of choice. And as it and its various iterations such sFlow, IPFIX and  others continue to expand the breadth of context it provides network engineers, that margin is set to increase in its favor as time.

8 Keys to Understanding NetFlow for Network Security, Performance & Overall IT Health

Two Ways Networks Are Transformed By NetFlow

According an article in techtarget.com “Your routers and switches can yield a mother lode of information about your network–if you know where to dig.”  The article goes on to say that excavating and searching through endless traffic data and logs manufactured by your network system is a lot like mining for gold, and punching random holes to look for a few nuggets of information isn’t very efficient. Your search will be much more fruitful if you know where to look and what it will look like. Fortunately, the data generated by a NetFlow traffic reporting protocol yields specific information and you can easily sort, view and analyze the information into what you want to use or need.In contemporary networks, there is a need to collect and retain a good set of traffic records for several different purposes. These include the ability to monitor traffic for network planning, security and analysis as well as track traffic usage for billing purposes. Every business experiences network problems. The goal is to transform these “bad behaving” networks by investigating the data that is being generated by the routers, switches and other hardware that make up the system.

  • Trace and repair network misconfigurations

Problems with networks can run the gamut from mismatched applications and hardware to wireless access points opened to accommodate BYOD users and other business uses. While there is always talk about software flaws and news about the latest internet threat, those things often distract IT pros from the real, every-day threat of unstable networks that have been configured to accommodate legacy hardware and a multitude of software applications.

The increasing complexity of the Internet itself, with the interconnection of lots of different devices and device types adds to the challenge of operating a computer network. Even though developing protocols to respond to unpredicted failures and misconfigurations is a workable solution, these out-of-date configurations can still cause frequent problems and denial of service (DOS). With many modern network devices monitoring functions and gathering data, retrieving and utilizing the NetFlow information makes tracing and repairing the problem of misconfigurations possible, easier and efficient.

  • Detect security breaches

There are many uses for NetFlow but one of the most important is the benefit of network security. This quote from an article by Wagner and Bernhard, describing worm and anomaly detection in fast IP networks, bears out the security problems facing governments, businesses, and internet users today.

“Large-scale network events, such as outbreaks of a fast Internet worm are difficult to detect in real-time from observed traffic, even more so if the observed network carries a large amount of traffic. Even during worm outbreaks, actual attack traffic is only a small fraction of the overall traffic. Its precise characteristics are usually unknown beforehand, making direct matching hard. It is desirable to derive parameters that describe large amounts of traffic data in such a way that details are hidden, but the type of changes associated with worm outbreaks and other network events are visible.”

NetFlow provides a 24/7 account of all network activity. There is an “unblinking” eye observing anything and everything that happens within the network boundaries. All the data needed to identify and enact a clean-up is recorded in the flow and this is invaluable to a security pro trying to reduce the impact of a breach in the network. NetFlow provides a visible, “what’s happening right now” view that other systems cannot provide. Most security systems alert after something has been detected, while NetFlow is constantly gathering information even when things seem to be just fine. In addition, NetFlow-based analysis relies on traffic behavior and algorithms which provides rapid detection of breaches that other technologies often miss

8 Keys to Understanding NetFlow for Network Security, Performance & Overall IT Health