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QFX3500 VirtualCHassis Question

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  • 1.  QFX3500 VirtualCHassis Question

    Posted 08-11-2020 07:10

    Hello,

    i want to follow http://tawfique19.blogspot.com/2017/08/configuring-qfx5100-two-members-virtual.html and configure Virtual Chassis between my 2x QFX3500 and my top of rack switch has 2x 10G (one of them is connected to QFX3500 #1 and otherone is connected to QFX3500 #2) so i n this way if i follow http://tawfique19.blogspot.com/2017/08/configuring-qfx5100-two-members-virtual.html guide to configure virtual chassis :

    1) my top of rack switches has 20gbps (LACP) capacity and i have 20gbps throughput ? because i that link when execute show virtual-chassis one switch role is master and other one is backup , so i assume backup can not transfer data, am i right or i imagine wrongly?

    Thanks,



  • 2.  RE: QFX3500 VirtualCHassis Question

    Posted 08-11-2020 08:05

    Hello Blackmetal,

     

    You have a VC of two members and configured an AE interface with two child interfaces (10G interfaces). One link connects to one member and the second link connects to the second member. You want to know if the capacity of your AE will be 20gb, correct?

     

    Regards,



  • 3.  RE: QFX3500 VirtualCHassis Question
    Best Answer

     
    Posted 08-11-2020 08:24

    @blackmetal couple of mis-conceptions.  #1, Master/Backup pertain to RE (CPU) function within a [in your case] VC.  The RE is the one that learns info, and then populates ever member of the VC with same info.  This Master/Backup has nothing to do with how VC actually forwards traffic.  This is unlike Primary/Standby for say a FW where only one node forwards traffic, while other sits and waits to take over in Primary fails.  Master/Backup RE functions this way for learning, not for forwarding.

     

    Your AE/LAG is 20G but for any single flow the max throughput will be 10G.  Any single flow is always mapped (hashed) to same single 10G link.  You could get max of 20G of total throughput (depending upon hash and traffic) but for any single flow, max is 10G.

     

    HTH



  • 4.  RE: QFX3500 VirtualCHassis Question

    Posted 08-11-2020 08:32

    ah i got it,

    so when i execute show virtual chassis and it shows master/backup it shows which switch is distrubitng the data right? but the traffic is forwarded towards all VC members and all of them are forwarding same data to my router and i have 20gb throughput for my top of rack switches? (if we ignore single flow)



  • 5.  RE: QFX3500 VirtualCHassis Question

     
    Posted 08-11-2020 09:02

    distributing the learned data/info, and yes all other is correct.



  • 6.  RE: QFX3500 VirtualCHassis Question

    Posted 08-11-2020 09:22

    and if first qfx3500 fail then the second qfx350 will handle data/info and so totally i have 2x throughtput and redundancy ?



  • 7.  RE: QFX3500 VirtualCHassis Question

     
    Posted 08-11-2020 09:34

    For failure you have redundancy, but throughput cut in half.



  • 8.  RE: QFX3500 VirtualCHassis Question

    Posted 08-11-2020 09:41

    your mean is when one of my VC member fail my throughput cut in half, right? in general when i have 2 member it will be 20gbps?



  • 9.  RE: QFX3500 VirtualCHassis Question

     
    Posted 08-11-2020 11:49

    yes



  • 10.  RE: QFX3500 VirtualCHassis Question

    Posted 08-11-2020 08:29

    yes thats right,

    i have 2x qfc3500 and configured them in virtual chassis way as i read http://tawfique19.blogspot.com/2017/08/configuring-qfx5100-two-members-virtual.html 

    and my top of rack switches first 10g is conected to qfx3500 #1 and secon 10gb is connected to qfx3500 #2 and i ave configure AE in my top of rack switch,

    so if i configure AE in qfx side, do i have 20gb throughput? if yes, why does when i execute show virtual chassis it shows one of them as master and other one as backup ?

    because as i know the when a switch is in backup mode its in standby