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Enabling Jumbo Frames on virtual distributed switches (1038827)

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Purpose

This article provides information about enabling Jumbo Frames in a virtual distributed switch.

Resolution

To enable Jumbo frames in a virtual distributed switch ( vDS), follow these steps:
    1. Globally, so that all portgroups and ports in the vDS have Jumbo Frames enabled
    2. At the VMkernel port, so that only specific VMkernel ports are configured with Jumbo Frames (usually configured for iSCSI or NFS storage).
    Note: Ensure that your network card, physical switches, and storage devices support Jumbo Frames before configuring.

    Enabling Jumbo Frames for all portgroups or ports

    You can configure the MTU value of a vDS switch so that all portgroups and ports use Jumbo Frames.

    Note: Any new ports created after adjusting the setting use Jumbo Frames. Existing ports are not affected.
     
    To configure Jumbo Frames on a vDS using vSphere Client on vCenter Server 5.1 and earlier:
    1. From vCenter Server click, click Home > Inventory > Networking.
    2. Right-click the vDS and click Edit Settings.
    3. On the Properties tab, select the Advanced option.
    4. Change the Maximum MTU value from the default value of 1500 to 9000. This enables Jumbo Frames on all portgroups and ports.
    To configure Jumbo Frames on a vDS in vSphere Web Client for vCenter Server 5.1, vCenter Server 5.5 and vCenter Server 6.0:
    1. Browse to a distributed switch in the vSphere Web Client navigator.
    2. Click the Manage tab, and click Settings > Properties.
    3. Click Edit.
    4. Click Advanced and set the MTU property to a value greater than 1500 bytes.

      Notes:
      • You cannot set the MTU size to a value greater than 9000 bytes.
      • When changing the MTU size in a vDS, the attached uplinks (physical NICs) are brought down and up again. This causes a short network outage for virtual machines that are using the uplink.

    5. Click OK.

    Enabling Jumbo Frames on a VMkernel port from the vCenter Server

    To enable Jumbo Frames on a VMkernel port from vCenter Server 5.1 and earlier:
    1. Click Home > Hosts and Clusters > Host > Configuration > Networking.
    2. Navigate to the vSphere Distributed Switch tab.
    3. Click the VMkernel port (For example: vmk1)
    4. Click Manage Virtual Adapters.
    5. Select the vmk interface and click Edit.
    6. Under the NIC settings, change the MTU value to 9000.
    7. Click OK.
    To enable Jumbo Frames on a VMkernel port using the vSphere Web Client in vCenter Server 5.1, vCenter Server 5.5 and vCenter Server 6.0:
    1. In the vSphere Web Client, navigate to the distributed switch.
    2. On the Manage tab, click Settings and select Properties.
    3. Click Edit.
    4. Click Advanced and set the MTU value to 9000.

      Note: You can increase the MTU size up to 9000 bytes.

    5. Click OK.
    6. In the vSphere Web Client, navigate to ESXi host.
    7. On the Manage tab, select Networking and then select VMkernel adapters.
    8. Select a VMkernel adapter from the adapter table.
    9. Click the name of the VMkernel adapter.
    10. Click Edit.
    11. Select NIC settings and set the MTU property to a value greater than 1500.

      Note: You can increase the MTU size up to 9000 bytes.

    12. Click OK.

    Enabling Jumbo Frames on a VMkernel port in ESX/ESXi 4.1, ESXi 5.x and ESXi 6.0 from SSH/console:

    To enable Jumbo Frames on the existing VMkernel ports using SSH:
     
    This example shows how to enable Jumbo frames on VMkernel port vmk1 in a vDS called NewLAN-DVS:
    1. Get the vDS_name and DVPortID for the VMkernel port with the command:

      # esxcfg-vswitch -l

      You see output similar to:

      DVS Name Num Ports Used Ports Configured Ports MTU Uplinks
      NewLAN-DVS 256 23 256 1500 vmnic3,vmnic2,vmnic15

      DVPort IDIn UseClient
      115 1 vmk1

    2. Get network information (IP, Netmask, and PG/DV port name) for the VMkernel port with the command:

      # esxcfg-vmknic -l

      You see output similar to:


      Interface Port Group/DVPort IP Family IP Address Netmask Broadcast MAC Address MTU TSO MSSEnabled Type
      vmk1 115 IPv4 172.32.10.71 255.255.255.0 172.32.10.255 xx:xx:xx:xx:xx:x1 1500 65535 true STATIC

      Note: You see this output if Jumbo Frames are not enabled because the MTU is set to 1500.

    3. Run this command to change the MTU size for the individual port group:

      # esxcfg-vmknic -m 9000 -v port_number -s dvs_switch_name


      For example:

      # esxcfg-vmknic -m 9000 -v 115 -s "NewLAN-DVS"

    4. Confirm that VMkernel port vmk1 is configured with Jumbo Frames enabled, run the command:

      # esxcfg-vmknic -l

      You see output similar to:

      Interface Port Group/DVPort IP Family IP Address Netmask Broadcast MAC Address MTU TSO MSSEnabled Type
      vmk1 115 IPv4 172.32.10.71 255.255.255.0 172.32.10.255 xx:xx:xx:xx:xx:x2 9000 65535 true STATIC

    Enabling Jumbo Frames on a VMkernel port in ESX/EXi 4.0 from SSH/console:

    You can only enable Jumbo Frames on VMkernel ports when they are being created. If the vDS does not have Jumbo Frames enabled, you can only configure this setting for a VMkernel port from a console or SSH/Putty session.
     
    If you have existing VMkernel ports and you want to enable Jumbo Frames on them, you have to delete and recreate them.
     
    This example shows how to delete the VMkernel port vmk1 in a vDS called NewLAN-DVS and recreate it with Jumbo Frames support enabled:
    1. Get the vDS_name and DVPortID for the VMkernel_port with the command:

      # esxcfg-vswitch -l

      You see output similar to:

      DVS Name Num Ports Used Ports Configured Ports MTU Uplinks
      NewLAN-DVS 256 23 256 1500 vmnic3,vmnic2,vmnic15

      DVPort IDIn UseClient
      115 1 vmk1

    2. Get network information (IP, Netmask, and PG/DV port name) for the VMkernel port with the command:

      # esxcfg-vmknic -l

      You see output similar to:

      Interface Port Group/DVPort IP Family IP Address Netmask Broadcast MAC Address MTU TSO MSSEnabled Type
      vmk1 115 IPv4 172.32.10.71 255.255.255.0 172.32.10.255 xx:xx:xx:xx:xx:x4 1500 65535 true STATIC

      Note: You see this output if Jumbo Frames are not enabled because the MTU is set to 1500.

    3. Delete the VMkernel_port for vmk1 with the command:

      # esxcfg-vmknic -d -s DVS_Name -v DVPort_ID Portgroup/DVPort_Name

      To delete VMkernel port vmk1 that is defined in the output in step 2, run this command:

      # esxcfg-vmknic -d -s "NewLAN-DVS" -v 115 115

      Note: In this example, the DVPort_Name is named as 115.

    4. Create the new VMkernel port for vmk1 with Jumbo Frames ( MTU 9000) with the command:

      # esxcfg-vmknic -a -i IP -n Netmask -m 9000 - s DVS_Name -v DVPort_ID Portgroup/DVPort Name

    5. To recreate vmk1 with the same configuration and Jumbo Frames enabled, run this command:

      # esxcfg-vmknic -a -i 172.32.10.71 -n 255.255.255.0 -m 9000 -s "NewLAN-DVS" -v 115 115

    6. Confirm that VMkernel port vmk1 is configured with Jumbo Frames enabled, run this command:

      # esxcfg-vmknic -l

      You see output similar to:

      Interface Port Group/DVPort IP Family IP Address Netmask Broadcast MAC Address MTU TSO MSSEnabled Type
      vmk1 115 IPv4 172.32.10.71 255.255.255.0 172.32.10.255 xx:xx:xx:xx:xx:x5 9000 65535 true STATIC

    Additional Information

    For more information on configuring Jumbo frames, see iSCSI and Jumbo Frames configuration on ESX/ESXi (1007654). Jumbo frames must be configured similarly across the board on both virtual and physical infrastructure, such as vSwitch, Portgroups, VMkernel, and physical switch port.

    For more information on troubleshooting host Jumbo Frame issues, as well as how to test that Jumbo Frame connectivity is working as it should be, see Troubleshooting disk latency when using Jumbo Frames with iSCSI or NFS datastores (2002197).

    See Also

    Update History

    12/17/2012 - Added link to article 1007654 10/07/2013 - Added ESXi, vCenter 5.1 and 5.5

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