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  • 1.  Loops Prevents on QFX5100

    Posted 03-01-2022 05:33
    Hi All
    Some body can help me please ?

    I am facing a dilemma I currently have two datacenters and I plan to deploy a 3rd and I need to communicate two vlans the 4060 and 4061 in the three datacenters
    However my concern is that it will loop
    Do you have any idea of ​​what protocol I can use to avoid this knowing that I don't want to use STP or RSTP or TRILL or 802.1aq
    FYI I have juniper QFX5100 switches
    Someone told me about MC-LAG but I don't think MC-LAG can save me loops
    Please find below the architecture of my datacenter


    Thank you in advance



    ------------------------------
    Doumba Dowberdhe
    ------------------------------


  • 2.  RE: Loops Prevents on QFX5100

     
    Posted 03-01-2022 05:36
    With using layer 2 vlans between sites you will need to run STP (Spanning Tree Protocol) to prevent loops. 

    Your best options with the use of vlan trunk ports is either MSTP or VSTP in Junos.

    https://www.juniper.net/documentation/us/en/software/junos/stp-l2/topics/topic-map/spanning-tree-overview.html

    ------------------------------
    Steve Puluka BSEET - Juniper Ambassador
    IP Architect - DQE Communications Pittsburgh, PA (Metro Ethernet & ISP)
    http://puluka.com/home
    ------------------------------



  • 3.  RE: Loops Prevents on QFX5100

    Posted 03-01-2022 09:42
    Hi Mr Spuluka 
    Thank you for your answer and for your helps 

    I forgot to specify that between datacenter 1 and 2 we have a links  aggregation in which we use storm-control we do not use STP between our datacenters today


    Is your answer still valid?

    And we plan to use a links aggregation between  DATACENTER 1 to DATACENTER 3  and DATACENTER 2 to DATACENTER 3
    thank you in advance



    ------------------------------
    Doumba Dowberdhe
    ------------------------------



  • 4.  RE: Loops Prevents on QFX5100

     
    Posted 03-02-2022 05:50
    By adding links to both original DC from the new third location you are creating a loop where the traffic can link around all three.  So you will need to enable some technology that keeps one of the links inactive until such time as one of the other two links fails.

    You do not have this problem until you add the two links from the new DC.

    ------------------------------
    Steve Puluka BSEET - Juniper Ambassador
    IP Architect - DQE Communications Pittsburgh, PA (Metro Ethernet & ISP)
    http://puluka.com/home
    ------------------------------



  • 5.  RE: Loops Prevents on QFX5100

    Posted 03-01-2022 09:42
    If your using Cisco in any DC go with VSTP , else MSTP is the way to go.   
    One other option that may be useful
    ERPS

    Ethernet ring protection switching (ERPS) helps to prevent fatal loops from disrupting a network. ERPS is similar to spanning-tree protocols, but ERPS is more efficient because it is customized for ring topologies.

    I think its a 50ms convergence time on it .  I have never ran it.


  • 6.  RE: Loops Prevents on QFX5100

     
    Posted 03-01-2022 13:28
    Hi,

    1. STP
    2. ERPS
    3. Static vxlan
    4. EVPN vxlan
    5. L2 over MPLS
    6. MC-LAG