KVM network packet loss to guest












1














I am running a server with Debian 8.3, uname output



Linux x 3.16.0-4-amd64 #1 SMP Debian 3.16.7-ckt20-1+deb8u3 (2016-01-17) x86_64 GNU/Linux


I am using KVM to run a virtual machine with CentOS 7.2.1511 inside it, there are two network interfaces on the host and two network interfaces on the guest using bridges and virt-io.



One of the network interfaces is used for receiving multicasts (around 300mbps, received on the host's eth1 device) and it has packet loss, with the dropped packets visible on the host on "vnet1" interface. I increased the txqueuelen of the interface and the drop counter no longer increases, but packets are still lost.



I tried using virt-io, e1000 and rtl8139 drivers and macvtap (passtrough mode), it all results in more or less packet loss which is a big problem for multicasts. The server cpu usage is low.



How do I make the virtual network behave correctly.










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    1














    I am running a server with Debian 8.3, uname output



    Linux x 3.16.0-4-amd64 #1 SMP Debian 3.16.7-ckt20-1+deb8u3 (2016-01-17) x86_64 GNU/Linux


    I am using KVM to run a virtual machine with CentOS 7.2.1511 inside it, there are two network interfaces on the host and two network interfaces on the guest using bridges and virt-io.



    One of the network interfaces is used for receiving multicasts (around 300mbps, received on the host's eth1 device) and it has packet loss, with the dropped packets visible on the host on "vnet1" interface. I increased the txqueuelen of the interface and the drop counter no longer increases, but packets are still lost.



    I tried using virt-io, e1000 and rtl8139 drivers and macvtap (passtrough mode), it all results in more or less packet loss which is a big problem for multicasts. The server cpu usage is low.



    How do I make the virtual network behave correctly.










    share|improve this question

























      1












      1








      1







      I am running a server with Debian 8.3, uname output



      Linux x 3.16.0-4-amd64 #1 SMP Debian 3.16.7-ckt20-1+deb8u3 (2016-01-17) x86_64 GNU/Linux


      I am using KVM to run a virtual machine with CentOS 7.2.1511 inside it, there are two network interfaces on the host and two network interfaces on the guest using bridges and virt-io.



      One of the network interfaces is used for receiving multicasts (around 300mbps, received on the host's eth1 device) and it has packet loss, with the dropped packets visible on the host on "vnet1" interface. I increased the txqueuelen of the interface and the drop counter no longer increases, but packets are still lost.



      I tried using virt-io, e1000 and rtl8139 drivers and macvtap (passtrough mode), it all results in more or less packet loss which is a big problem for multicasts. The server cpu usage is low.



      How do I make the virtual network behave correctly.










      share|improve this question













      I am running a server with Debian 8.3, uname output



      Linux x 3.16.0-4-amd64 #1 SMP Debian 3.16.7-ckt20-1+deb8u3 (2016-01-17) x86_64 GNU/Linux


      I am using KVM to run a virtual machine with CentOS 7.2.1511 inside it, there are two network interfaces on the host and two network interfaces on the guest using bridges and virt-io.



      One of the network interfaces is used for receiving multicasts (around 300mbps, received on the host's eth1 device) and it has packet loss, with the dropped packets visible on the host on "vnet1" interface. I increased the txqueuelen of the interface and the drop counter no longer increases, but packets are still lost.



      I tried using virt-io, e1000 and rtl8139 drivers and macvtap (passtrough mode), it all results in more or less packet loss which is a big problem for multicasts. The server cpu usage is low.



      How do I make the virtual network behave correctly.







      linux debian networking kvm






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      asked Feb 1 '16 at 9:21









      Pentium100

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          Try looking at disabling some of the nic offloading features (ethtool -k/-K tso, gro, sg, etc)



          I found the solution to my problem here.






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          1 Answer
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          active

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          active

          oldest

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          active

          oldest

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          0














          Try looking at disabling some of the nic offloading features (ethtool -k/-K tso, gro, sg, etc)



          I found the solution to my problem here.






          share|improve this answer



















          • 3




            Welcome to StackExchange! When using a link in an answer, please provide some context, such as quoting the relevant part.
            – JigglyNaga
            Aug 23 '16 at 15:45
















          0














          Try looking at disabling some of the nic offloading features (ethtool -k/-K tso, gro, sg, etc)



          I found the solution to my problem here.






          share|improve this answer



















          • 3




            Welcome to StackExchange! When using a link in an answer, please provide some context, such as quoting the relevant part.
            – JigglyNaga
            Aug 23 '16 at 15:45














          0












          0








          0






          Try looking at disabling some of the nic offloading features (ethtool -k/-K tso, gro, sg, etc)



          I found the solution to my problem here.






          share|improve this answer














          Try looking at disabling some of the nic offloading features (ethtool -k/-K tso, gro, sg, etc)



          I found the solution to my problem here.







          share|improve this answer














          share|improve this answer



          share|improve this answer








          edited Aug 23 '16 at 15:48









          HalosGhost

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          3,70592235










          answered Aug 23 '16 at 15:32









          kyleo

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          32








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            Welcome to StackExchange! When using a link in an answer, please provide some context, such as quoting the relevant part.
            – JigglyNaga
            Aug 23 '16 at 15:45














          • 3




            Welcome to StackExchange! When using a link in an answer, please provide some context, such as quoting the relevant part.
            – JigglyNaga
            Aug 23 '16 at 15:45








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          3




          Welcome to StackExchange! When using a link in an answer, please provide some context, such as quoting the relevant part.
          – JigglyNaga
          Aug 23 '16 at 15:45




          Welcome to StackExchange! When using a link in an answer, please provide some context, such as quoting the relevant part.
          – JigglyNaga
          Aug 23 '16 at 15:45


















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