Random Netflow – A Tool to Keep in Your Kit

In my network management adventures throughout the years, I’ve found Netflow to be an invaluable tool to troubleshoot a range of network issues – from bandwidth to service and resource problems. It’s an amazing traffic mining tool – it analyzes traffic flows across a network and provides a huge amount of information. That is where the problem lies as well – sometimes Netflow delivers too much information when I just want a small amount data for planning and traffic engineering. I’m sure you’ve come across this issue – right?

I know I’m not the only one, since I came across a great article from Network World on how to solve this issue. The advice is very straight forward and concise on how to solve the information overload issue by using the random Netflow feature. Thought it was worth sharing.

A few of my favorite tips from the article:

- Know your flow. Netflow versions 5 or 9 work if you need to export the data to look at it off device. With other versions you can view the data on the device.

- You can not have Netflow enabled on an interface you want to run random Netflow on. A device always gives full Netflow precedence over random Netflow.

- If you run into any problems there is a debug command: debug flow-sampler.

What was your favorite tip? Or if you have one that isn’t mentioned, I’d love to hear it!

Announcing the release of dopplerVUE 2.0

dopplerVUE 2.0 is now available for download with exciting new features including discovering and mapping HSRP primary and secondary links, a new interface with graphics for better visibility, improved SNMP table polling and more! The 30-day trial is free, just like it was for the pre-release.

OPSCenter Screenshot

Netflow Screenshot















For those of you who missed the pre-release announcement, here’s the new feature list:

• New interface with new graphics for better readability
• Manage ANY metric on ANY device with improved SNMP table polling
• Discover and map HSRP primary and secondary links
• New WMI wizard
• Easily create personal workspaces with the new dVUE templates
• Distributed architecture to extend the number of managed devices
• Improved database and architecture for increased performance

Plus - for distributed enterprise networks dopplerVUE connects with NeuralStar to create a two-tiered, centrally monitored, fully replicated enterprise network management system that provides:

• Increased fault tolerance
• Improved performance through load balancing
• Powerful disaster recovery capabilities
• Enhanced scalability

I’d love to hear any dopplerVUE or network-related comments or questions you have!

Looking to Reduce IT Costs…Optimize Network Traffic

In these days of pinching pennies and saving dimes, the best way to help your organization is to find ways to reduce costs. Do you know which network resources are costing you the most? Answering this question can lead to optimizing network traffic and cutting costs.

For instance, the cost of LAN traffic within your office is usually fairly affordable, however, once the packets hit the WAN, the price tag increases significantly.

You can use Netflow to identify which network resources are adding the most to your monthly bill. Start monitoring the circuits that make up the majority of your high cost list with Netflow and you might find some network efficiencies that lead to savings that have a big financial impact.

To find cost savings, I use a network management tool, dopplerVUE, that has a bandwidth locator that sorts and finds top bandwidth users in networks. dopplerVUE provides Netflow support to give you multiple ways to view traffic in your network.

If you want more details on where all your traffic is going and how to configure Netflow to give you the answers, check out this recent post.