We're Sorry, Full Content Access is for Members Only...

If you like to keep on reading, Become a Member Now! Here is why:

  • Learn any CCNA, CCNP and CCIE R&S Topic. Explained As Simple As Possible.
  • Try for Just $1. The Best Dollar You've Ever Spent on Your Cisco Career!
  • Full Access to our 651 Lessons. More Lessons Added Every Week!
  • Content created by Rene Molenaar (CCIE #41726)

461 Sign Ups in the last 30 days

100% Satisfaction Guaranteed!
You may cancel your monthly membership at any time.
No Questions Asked!

Tags: , ,

Forum Replies

  1. Hi Ruben,

    If you want to see statistics with “show ip sla” then you’ll need to add the responder on the receiver. In this example, all I needed was to generate some traffic.


  2. Hi Rene,

    I was wondering, can a test like this be used to lets say sweep a range from lets say 16k to 1M on TCP or UDP and then check up until which load it was successful?
    A test like that would be useful to have to measure the actual speed of a link like for DSL over ATM or metro ethernet.
    I have always been looking for something like that.

  3. Hi Rene,

    You use ethernet frame header for calculations. Why you not take care of FCS(4 bytes) and EtherType (2 bytes)?. Total ethernet length shoud be :

    8 bytes of preamble + 12 bytes MAC + 2 bytes ethertype/lengt + payload + 4 bytes FCS = 26 bytes + 20 bytes IP + 8 bytes udp = 54 bytes. So you shoud use a payload of 46 bytes for a total frame size of 100 bytes. Is not that right?

    Thanks to you



  4. Hi Diego,

    There’s a difference between the L2 header and the “physically” transmitted frame. Here’s what belongs to the header:

    Destination MAC: 6 bytes
    Source MAC: 6 bytes
    Ethertype: 2 bytes
    FCS: 4 bytes

    That’s 18 bytes in total.

    The preamble (7 bytes) and start of frame delimited (1 byte) are not included with the L2 header.

    Hope this helps.


  5. HI Rene,

    Thank you for your article. I was looking for something to generate traffic like 200Mbps or more. I’ve tried iperf seems is not good. Do you have anything else to suggest or any approach to configure inside the routers?

18 more replies! Ask a question or join the discussion by visiting our Community Forum