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VCAP5-DCA Objective 2.4 : Administer vNetwork Distributed Switch Settings

  • Understand the use of command line tools to configure appropriate vDS settings on an ESXi host

There is very limited commands for a Distributed vSwitch through the command line, as you can understand its a way to centralize your networking configuration and really I think should be used when you have lost connection to the ESXi host and need to promote an extra NIC into the vDS. Depending on your flavor of access you can use either the vicfg-vswitch command from vMA or CLi or use esxcfg-vswitch directly SSH or console of the ESXi host.

I previously covered this in VCAP5-DCA Objective 2.1 : Implement and Manage Complex Virtual Networks

  • Determine use cases for and apply Port Binding settings

pg binding

There are 3 port binding options available:

Static binding – This is the default and when creating a port group you do not get a choice of what binding you want, this is a pet hate of mine as I then have to edit the setting of the port group after its been created to make any changes like port binding to it. This binding option permanently assigns a vNIC to a port at first power on, This port will remain assigned to the virtual machines vNIC(s) untill its is deleted or moved off the vDS.

Dynamic binding – Just as it sounds, when a VM is powered on it will assign port to the VMs vNIC(s) and once the VM is powered off that assignment is removed. This allows you to have more VMs then there are ports available.

Ephemeral – Basically acts the same way as a standard vSwitch, and will assign a port to a VM regardless of power state and will keep assigning ports untill the Maximum is met.

  • Configure Live Port Moving
  • Given a set of network requirements, identify the appropriate distributed switch technology to use

Well there really is only one other option out there and that’s the Cisco Nexus 1000v which Cisco have now made free for basic functionality anyway.

Why would you use a 1000v over a standard Distributed Switch, The only real reason is so your network admins can manage the networking from the physical into the virtual without learning new skills or needing to have access to the vSphere environment  the 1000v is managed just like any other Cisco switch and also comes with the ability to do things like firewalls, routing, vlaning etc

  • Configure and administer vSphere Network I/O Control

Best way to describe this is its a form of QoS, allows to determine bandwidth that different network traffic types are given. This is only available when using enterprise plus licencing. There is pre-defined resource pools as below:

    • Fault Tolerance traffic,
    • iSCSI traffic,
    • vMotion traffic,
    • management traffic,
    • vSphere Replication (VR) traffic,
    • NFS traffic,
    • virtual machine traffic.

by default virtual machine traffic is given high share setting.

New in vSphere 5 NIOC introduced user defined network resource pools

Its easy to enable, go to the networking home page, select a distributed switch and click on properties.

nioc enable b

And tick the only option available.

nioc enable

Now that it is enabled you can either assign the predefined network pools or create a custom one. Here we will create a custom one for category A applications.

Click on the new network resource pool on the top right.

custom resource pool d

Fill in the information required. You can assign a QoS tag if your network supports it, so QoS can be applied throughout the network not just within the ESXi hosts

custom resource pool

custom resource pool e

Now we can assign the new network resource pool to a port group, click on “manage port group” in the top right also.

custom resource pool f

custom resource pool b

Click on where it says none and a drop down menu will appear, assign this to the new gold pool we created.

custom resource pool c

Hit OK and its done

custom resource pool g

  • Use command line tools to troubleshoot and identify configuration items from an existing vDS

See the first item in this Objective. a good command I have not mentioned previously is net-dvs, this will return everything about the dvs switches. more of an information dump.

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