What is N-VDS or hostSwitch in NSX-T?

Posted by on in | 8,434 Views | 10 Responses

The NSX managed virtual distributed switch (N-VDS, previously known as hostswitch) or OVS is invisible to the tenant network administrator and provides the underlying forwarding. The primary component involved in the data plane of the transport nodes is the N-VDS. The N-VDS forwards traffic between components running on the transport node (e.g., between virtual
machines) or between internal components and the physical network. While configuring the hypervisor hosts or the NSX-T edges as Transport node, the admin must specify the Transport Zone, Uplink Profile and Physical Network adapters(pNICs). The N-VDS must own one or more physical interfaces (pNICs) on the transport node. The physical network adapters owned by the N-VDS cannot be shared with any another N-VDS. The N-VDS can coest with vSwitch, dvSwitch, another N-VDS when using a separate set of pNICs.

N-VDS implementation on ESXi and KVM:

On ESXi hypervisors, the N-VDS implementation is derived from VMware vSphere® Distributed Switch™ (VDS) through the nsx-vSwitch module. The nsx-vswitch module is loaded in to the kernel when the hypervisor host is configured as a Fabric Node. The N-VDS is a mandatory component for running the Overly network can coexists with the vSwitch, DVSwitch as long as they are configured with a different set of pNICs. The nsxa agent/process running on the ESXi host will configure the hostswitch with the help of the nsx-vswitch kernel module.

Run the following command to list the NSX Kernel modules on the ESXi host.

[root@esx-04a:~] esxcfg-module -l | grep nsx
01-esxcfg-module -l | grep nsx

To list the packages installed on the ESXi host, run the following command:

[root@esx-04a:~] esxcli software vib list | grep nsx

esxcli software vib list | grep nsx

On KVM hypervisor, the Open-vSwitch (OVS) module implements the Hostswitch. You may run the following command to check the list of the opevSwitch packages installed on the Ubuntu KVM host.

root@kvm-01a:~# dpkg -l | grep openvswitch-*
openvSwitch modules on KVM

List of packages installed on KVM, pushed from the NSX Manager are :

04-Debian Packages installed on the KVM

Conclusion:

In this blog post, we have discussed the following:

  • What is N-VDS or hostswitch?
  • How is the ESXi implements the N-VDs?
  • How is the KVM implements the N-VDs?
  • Packages installed on ESXi/KVM hosts?

For more information about the N-VDS, please do read the NSX-T Documentation:

I hope this is informative for you and thank you for reading.

Related Posts:

10 Responses

  1. How to create a Transport Node in NSX-T • Virtual Brigade
    How to create a Transport Node in NSX-T • Virtual Brigade at |

    […] What is N-VDS or hostSwitch in NSX-T? […]

  2. Arunabha Ghosh
    Arunabha Ghosh at |

    What if a standalone ESXi is being managed by NSX-T manager as it is vCenter independant, then how the N-VDS aka “hostswitch” will derive from? Is that Standard switch?

    Reply
    1. CHAND BASHA SHAIK
      CHAND BASHA SHAIK at |

      The NSX-T Data Center is designed to be a completely independent of the vCenter Server environment.
      To implement a hostswitch on a standalone ESXi host, the NSX-T Manager leverages the nsx-vswitch module installed on the ESXi host.
      The nsx-vswitch module is installed When the ESXi host is configured as a Fabric node. While configuring the ESXi as a transport node, the NSX-T host switch gets created with the nsx-vswitch module.
      The nsx-vswitch is forked from the etherswitch switch module.
      You can execute the following command to list the nsx vibs installed on the ESXi host:

      [root@esx-04a:~] esxcli software vib list | grep nsx
      nsx-aggservice
      nsx-common-libs
      nsx-ctxteng
      nsx-da
      nsx-esx-datapath
      nsx-exporter
      nsx-host
      nsx-hyperbus
      nsx-lldp
      nsx-metrics-libs
      nsx-mpa
      nsx-nestdb-libs
      nsx-nestdb
      nsx-netcpa
      nsx-platform-client
      nsx-python-protobuf
      nsx-rpc-libs
      nsx-sfhc
      nsx-shared-libs
      nsx-support-bundle-client
      nsxa
      nsxcli

      To list the modules, run the following command:
      [root@esx-04a:~] esxcfg-module -l | grep nsx
      nsx-core 11 16
      nsx-traceflow 4 20
      nsx-fc 5 516
      nsx-vswitch 15 304
      nsx-bfd 7 24
      nsx-switch-security 5 84
      nsx-kcp 4 172
      nsx-ipfix 0 60
      nsx-vdl2 6 548
      nsx-vdrb 1 436
      nsx-vsip 20 648
      nsx-dne 10 188

      On the KVM hypervisors, the nsx-t manager leverages OVS to implement the hostswitch

      Reply
  3. Verify hostswitch configuration on ESXi and KVM • Virtual Brigade
    Verify hostswitch configuration on ESXi and KVM • Virtual Brigade at |

    […] What is N-VDS or hostSwitch in NSX-T? […]

  4. How to create Logical Switches in NSX-T? • Virtual Brigade
    How to create Logical Switches in NSX-T? • Virtual Brigade at |

    […] What is N-VDS or hostSwitch in NSX-T? […]

  5. Connect KVM Virtual Machines to Logical Switches • Virtual Brigade
    Connect KVM Virtual Machines to Logical Switches • Virtual Brigade at |

    […] What is N-VDS or hostSwitch in NSX-T? […]

  6. Failed NSX-T Controller in a Control Cluster • Virtual Brigade
    Failed NSX-T Controller in a Control Cluster • Virtual Brigade at |

    […] What is N-VDS or hostSwitch in NSX-T? […]

  7. Install NSX Manager with ovftool • Virtual Brigade
    Install NSX Manager with ovftool • Virtual Brigade at |

    […] What is N-VDS or hostSwitch in NSX-T? […]

  8. NSX-T Manager Packages, Services and Logs • Virtual Brigade
    NSX-T Manager Packages, Services and Logs • Virtual Brigade at |

    […] What is N-VDS or hostSwitch in NSX-T? […]

  9. Upgrade Coordinator in NSX-T • Virtual Brigade
    Upgrade Coordinator in NSX-T • Virtual Brigade at |

    […] What is N-VDS or hostSwitch in NSX-T? […]

Leave a Reply