Bandwidth Monitoring – NetFlow or SNMP or maybe both ?

NetFlow Analyzer | January 19, 2010 | 2 min read
Talk about bandwidth monitoring and a default question is how. You have three options – Packet Sniffing (Packet Analysis), SNMP and NetFlow. When it comes to detailed traffic analysis, the choices are always packet sniffing and NetFlow and we talked about this in our last blog. When it comes to simple, no frills bandwidth monitoring, it is either SNMP or NetFlow. Which one do we go with now? SNMP based monitoring tools collects information about the Tx and Rx (Transmit and Receive) values from your network device interfaces. Using this you get information on the byte count (volume), from it the bits per second count (speed) and from that the utilization, thereby providing a clear and accurate information on interface-level bandwidth usage. Though the information from SNMP is not in-depth, it works with any device that supports SNMP (that is almost anything that has an Ethernet port on it) and gives you a good idea how much of a link is being utilized or has congestion. This has a great value in making capacity planning decisions.There might also be a number of unwanted applications in your network, using up the available bandwidth and causing bottlenecks. SNMP will not provide information on the applications used, IP/hosts involved, conversations, ToS, QoS and so on. So, important questions like who used the bandwidth, where did all the traffic go, what was the priority and much more is left unanswered. This is where NetFlow makes a difference.

NetFlow data gives information on applications used, source and destination of traffic, conversations, ToS, DSCP, QoS, NextHop and has capabilities for even video traffic monitoring and much more. Moreover, unlike SNMP, which is based on PULL technology where the monitoring tool has to pull data from the device MIB at set time intervals, NetFlow is based on PUSH technology, making it capable to show information as soon as it occurs by setting appropriate flow export time on the device. Further more, NetFlow also shows information on volume, speed and link utilization. So thats an all in one.

Was not much of a fight !

ManageEngine NetFlow Analyzer with its capabilities to report on data ranging from the last minute to forever with new features added almost every six months is one of the best value for money tools for flow analysis. Check out our 30 day, full feature trial by downloading from here.

My Two Cents:

Not all devices support NetFlow export but almost all devices support SNMP. For in-depth analytics use NetFlow and those who need to verify that the data (volume / speed / utilization) reported by NetFlow is indeed correct or need bandwidth usage reports from non-NetFlow supported devices, use SNMP. A combination of SNMP and NetFlow based solution is the ideal choice.

Try ManageEngine OpManager which uses SNMP to report on device health and utilization, interface status, packet drops, and a lot more and at the same time supports bandwidth reports using NetFlow. You can use either the NetFlow Plug-In to OpManager or integrate NetFlow Analyzer and OpManager.

Instead of having just one, use the power of both technologies and ensure your network is at its best.

Regards,
Don Thomas Jacob

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Tags : bandwidth monitoring / indepth traffic reports / link monitoring / monitoring / SNMP / SNMP vs NetFlow / traffic analysis
jacob@zohocorp.com

  1. Reply
    charlie ward

    Thanks for this post! As a network manager I was looking online for different SNMP Monitoring because as you know, you can’t have certain operations fail. That’s when I came across your blog post about Netflow or SNMP, very good read. I think I prefer SNMP, but using both of them is a idea I haven’t considered before. Thanks again for this!

  2. Reply
    Matthew

    Great article, explains exactly what I was looking for. Short and simple.

  3. Reply
    nandan

    nice write up…explains the topic perfectly