none
DHCP guard and Router guard

    Question

  • Hello

    Please tell me on your own words

    what is DHCP gaurd in hyper v?

    What is Router guard in hyper v?

    What is Protect Network in hyper v?

    What is Port mirroring in hyper v?

    thanks


    Monday, March 20, 2017 12:33 AM

All replies

  • Hello,

    >>> DHCP Guard

    If the VM is a DHCP server, and with DHCP guard enabled, DHCP guard stops the virtual machine (DHCP Server) from making DHCP offers over this network interface.

    Usually, this feature can be used in a scenario as below.

    A VM has installed DHCP, and it has multiple NICs, which are connected to several networks. If you only want VM to offer DHCP service to one specific  network, then DHCP guard should be enabled on the other NICs, or networks.

    >>> Router Guard

    Router guard is similar as DHCP guard.

    When you enable Router Guard Hyper-V switch will discard the following packets:

    ICMPv4 Type 5 (Redirect message)
    ICMPv4 Type 9 (Router Advertisement)
    ICMPv6 Type 134 (Router Advertisement)
    ICMPv6 Type 137 (Redirect message)

    Imagine you have a virtual machine that is configured for routing services and is connected to multiple virtual networks.  You want to make sure that routing services are only provided on one specific virtual network.  In this case you would enable the router guard on any networks where you did not want the virtual machine to act as a router.

    >>> Protected Network

    Protected Network is useful for Hyper-V clustering.

    This feature enables to detect if the virtual switch that is used for this virtual network adapter has a link failure. If detected failure, the VM will be moved to another node in the cluster.

    >>> Port mirroring

    Port mirroring also called as SPAN, is a method to copy all the packets hitting one port, called source port, to another port, usually called destination port. This technology is usually used for monitoring network traffic, or analyzing and troubleshooting network issue.

    For example, if you want to monitor the traffic going to and from a web server, you can configure port mirroring on the NIC for the web server, and set the port as source. Then, you deploy a monitoring server, and configure port mirroring on the NIC for the monitoring server, and set the port as destination. All the traffic going to and from the web server, will be copied to the monitoring server.

    Best regards
    Andy Liu

    Please remember to mark the replies as answers if they help.
    If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com.

    Tuesday, March 21, 2017 12:32 AM
  • hello

    Its mean, if i have VM and DHCP server is installed on it. there are 2 network cards. one network card is configured 10.0.0.1 and 2nd network card is configured 192.0.0.1

    Now i want that DHCP only provide services for 10.0.0.0 network.

    in this case we will enable dhcp guard on that network card which we have configured 192.0.0.1 ??

    Please Define me also Device naming and NIC teaming.

    I know about NIC teaming. just tell me if we check NIC teaming option then what will happen?

    Tuesday, March 21, 2017 10:57 PM
  • Hello,

    >>> in this case we will enable dhcp guard on that network card which we have configured 192.0.0.1 ??

    Yes, you only enable guard for the vNIC, which will be provented from providing DHCP service. In your scenario, it's the vNIC with 192.0.0.1.

    >>> Device naming

    The following article explains Device naming very clearly.

    https://blogs.msdn.microsoft.com/virtual_pc_guy/2016/06/10/network-device-naming-in-hyper-v/ 

    >>> just tell me if we check NIC teaming option then what will happen?

    This option enables this network adapter to be part of a team in the Guest OS. If this opition is enabled, it will not affect the network connectivity of the VM. You still need to create a new team in the VM. 

    Please refer to the following articles.

    https://technet.microsoft.com/windows-server-docs/networking/technologies/nic-teaming/create-a-new-nic-team-in-a-vm
    https://technet.microsoft.com/windows-server-docs/networking/technologies/nic-teaming/create-a-new-nic-team

    Best regards,
    Andy Liu 

    Please remember to mark the replies as answers if they help.
    If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com.


    Wednesday, March 22, 2017 2:58 AM
  • Hello

    Can you give me example of device naming?

    Wednesday, March 22, 2017 10:15 PM
  • Hello,

    Firstly, you can now specify a network adapter name, for example  'Test 1' for one virtual network adapter in Powershell, please see the screenshot as below.



    Then, if you enable Device Naming on the virtual network adapter, this name will be exposed into the VM, and you can access the name either from the adapter advanced properties, or you can run Get-NetAdapterAdvancedProperty –DisplayName “Hyper-V Network Adapter Name”. This can help you find the network adapter easily in the guest operating system.



    Best regards,
    Andy Liu

    Please remember to mark the replies as answers if they help.
    If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com.

    Thursday, March 23, 2017 2:52 AM