What is Flexible NetFlow and why should you use it? In this blog post, let’s take a look at the basics of Application Visibility in the network for capacity planning and security.
In an enterprise, hundreds of applications are accessed by users from different locations within the campus and remotely from a branch or home. The application usage is usually not known beforehand and increases non-uniformly over time. This non-uniform app usage translates to non-uniform increases in traffic across the network which complicates capacity planning. Another complexity to capacity planning is that there can be sudden spikes in the traffic due to security issues such as internal security breaches, viruses, Denial of Service attacks, or network-propagated worms. IT administrators should not wait for these incidents to happen in order to tackle them. Instead, administrators must have the ability to see the usage pattern in advance for capacity planning and security incident detection and remediation.
I was driving home the other day when I heard a radio report on densely populated California cities. What’s interesting was a mention of a small California city that is ranked as the nation’s fourth most dense urbanized area. I guess that a lot of people don’t know Delano, a central valley city with a population density of 5,483 people per square mile. It’s surprisingly more dense than the New York-Newark, N.J. metropolitan area which is ranked the 5th.
Many people with many devices in a densely populated area can pose a challenge to WiFi networks. I was talking to a Cisco customer in the New York City area a few days ago. He said that deploying WiFi was not as straightforward as it used to be. There are many RF interferences near his office and many new SSIDs that he never saw before.
This is the fourth and final blog in a series of campus switching innovation blogs that share our recent switching launch news from Cisco Live London.
How many times have you heard that IT cannot take on as many new projects as they would like to because their resources are tied up to keep the house running? That IT could do much more to drive business growth only if they had more resources?
We announced a number of innovations at Cisco Live London earlier this month, including Cisco Catalyst SmartOperations – a suite of about a dozen tools that offer built-in intelligence on Cisco Catalyst switches for easing many challenges faced by network administrators in their day-to-day tasks. And because most of the tools are included in the base software image, they deliver productivity savings without adding cost!
I’ve had some recent discussions with colleagues in the armed forces regarding cyber security and how they consider “cyber” to be the fourth warfighting domain along with land, air, and sea. They describe how cyber has its own terrain made up of computing resources. As I further thought through this concept I saw a striking resemblance between the network and air warfare. To elaborate on this thought I must first set the context around the concept of air supremacy.
There are probably many different variations of the definition of air supremacy but let’s just use “the degree of air superiority wherein the opposing air force is incapable of effective interference” for the purpose of this blog. I borrowed this definition from NATO. There are two key words in the definition, “degree” and “effective.” Prior to achieving supremacy one must first move from parity, through superiority to eventually supremacy. Air parity is the lowest degree in which a force can control the skies above friendly units. In other words, prevention of opposing air assets from overwhelming land, air, and sea units. Read More »
For those of you that have been around the networking world for a while, NetFlow is far from a new technology. Cisco developed NetFlow years ago and it has become the industry standard for generating and collecting IP traffic information. NetFlow quickly found a home within network management providing valuable telemetry for overall network performance and management. Nine versions later NetFlow is growing in popularity not solely due to its value to network management but as a critical component of security operations. Over the past 12 months I have encountered more and more large enterprises that view NetFlow as one of their top tools for combating advanced threats within their perimeters.
The dynamic nature of the cyber threat landscape and growing level of sophistication and customization of attacks are requiring organizations to monitor their internal networks at a new level. IP flow monitoring (NetFlow) coupled with security focused NetFlow collectors like Lancope’s StealthWatch is helping organizations quickly identify questionable activity and anomalous behavior. The value that NetFlow provides is unsampled accounting of all network activity on an IP flow enabled interface. I bring up unsampled because of its importance from a security perspective. While flow sampling is a valid method for network management use cases sampling for the sake of security leaves too much in question. An analogy would be having two different people listen to the same song. One person gets the song played in its entirety, unsampled, and the other only hears the song in 30-second intervals. While neither may be musically inclined the person who had the advantage of listening to the song in its entirety would be able more accurately hum or sing back that song than the person that only heard 30 second snippets of the song. Furthermore the ability to identify that song during radio airplay would be in favor of the individual that was able to listen to the song in its entirety. This holds true for IP flow information when leveraging the information for detecting malicious or anomalous traffic. Some malicious code will only send a single packet back to a master node, which would most likely be missed, in a sampling scenario.
Further increasing the value of IP flow monitoring is Cisco’s recent release of Flexible NetFlow (FnF). FnF introduces two new concepts to flow monitoring. The first is the use of templates and the second expands the range of packet information that can be collected as well as monitor more deeply inside of a packet. This allows greater granularity in the information that is to be monitored as well a providing different collector sources for different sets of information. You can search for Flexible NetFlow on Cisco’s main website to get more technical details.
Are you using NetFlow for security operations? I welcome any feedback, good or bad regarding your experience and opinions on the value that IP flow information provides for detecting this ever-changing threat landscape.