DC. Part 1. EVPN/VXLAN for Data Centre with Nokia (Alcatel-Lucent) SR OS and Cisco IOS XR

Anton Karneliuk. IT & Network Expert / Architect / Manager; Project Manager; Entrepreneur; 2x CCIE (RS/SP) #49412; MSc Telecommunications.

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  1. Hi,
    Can you please help me. How can i create wireshark dumps on router and download the wireshark file on our system.

    Many thanks!!! for your support

  2. Hi Anton,

    Awesome article.

    I am new to VXLAN, and tried to simulate it using Arista vEOS all across the topology.

    What I want to ask is that, is that possible to have the VXLAN working without using any of overlay technologies such as EVPN, Multicast, etc. ? I’ve tried only use OSPF as underlay IP network and then configured VXLAN and its component. And somehow it works. But I don’t know how, because I don’t have many knowledge yet for VxLAN

    Thank you,

    1. Hi Fakhri,

      Thanks for the feedback.

      VXLAN is just encapsulation type, which is used to transmit some traffic over the network. How do you use it, it’s up to your. EVPN or Multicast is technology that helps to assure proper information distribution (processing of BUM traffic, then proper unicast traffic). I don’t know your setup, to explaing how it somehow working 🙂 For therory you could refer to some online articles (as I’m not writing about theory 🙂 ) or to some books, like http://www.ciscopress.com/store/building-data-centers-with-vxlan-bgp-evpn-a-cisco-nx-9781587144677



  3. Hi Anton,

    Thank you for the reply and the link it is useful.

    I think I already figure out how my setup is working. Arista can handle BUM traffic by using Head End Replication (HER) or (I cannot verify whether it is true or not) OTV in cisco NX-OS. By using HER we are defining the list of desired VTEP that we want to flood on each switches, this can be done manually or automatically using arista Cloud Vision (CVX).

    And just like using eBGP as underlay network technology, OSPF is only to provide underlay IP connectivity and HER is doing the rest to carry VXLAN traffic.

    Maybe, In my opinion, for larger network using OSPF and HER is not very scalable.

    Btw: here is my topology if you’re interested



    1. Hi Fakhri,

      you are describing HER correct, the point that it must be done, as I told, there is no magic. So you have manually added the list of endpoints for your VXLAN, so the endpoint knows how to treat BUM.
      Regarding scalability, well, there is no single answer. HER is used in BGP-EVPN as well, it’s just another type of control plane, not the data plane, which stays with VXLAN. So we need to distinguish:
      1) Control plane: how you VTEP about other VTEPs and associated routes (manuall, multicast group or BGP-EVPN).
      2) Data plane: how you send the traffic (VXLAN/MPLS) and how you treat BUM (HER or multicast)
      Normally BUM traffic is very low, like less 1% of the communication, so HER is OK. but for sure, it depends on your applications.

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