Forum Replies

  1. Hi,
    Can you explain about netflow vs sflow and how to implement sflow on cisco isr routers ?
    Thanks

  2. Hi Mr M Y,

    The NetFlow cache in a router is limited. By default, active flows are removed from the cache after 30 minutes.

    You might like the information from this Cisco article:

    After you enable NetFlow on an interface, NetFlow reserves memory to accommodate a number of entries in the NetFlow cache. Normally, the size of the NetFlow cache meets the needs of your NetFlow traffic rates. The cache default size is 64K flow cache entries. Each cache entry requires 64 bytes of storage. About 4 MB of DRAM are required for a cache with the default number of entries. Y

    ... Continue reading in our forum

  3. Hello Rene,

    I was reading an article about Netflow specific to IOS XE. I read a few terms called :

    1. Netflow Monitor
    2. Flow record
    3. netflow exporter

    can you please help in understanding how they are separate from each other ?

    Thanks
    Abhishek

  4. Hi Diana,

    It’s best to check the NTOP website for this. I used NTOP since it’s open source and available to everyone.

    If I would write about NTOP, the information is probably outdated in a few months.

    Rene

  5. I think a typo here see below you say “Can`t” I think you mean “can”??

    One of the things we can’t do with those tools is tracking all flows in our network. A flow is a stream of packets that share the same characteristics like source/destination port, source/destination address, protocol, type, service marking, etc.

    NM you was talking about SNMP and NBAR not Netflow I see now. my bad.

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