Активация Jumbo Frames в гостевой ОС (Windows Server 2012)

На уровне гостевой ОС (в нашем примере это Windows Server 2012) включается аналогично гипервизору: в расширенных настройках драйвера укажите, что Jumbo Packet=9014 Bytes.

Тестируем работу Jumbo Frames в Windows

В большинстве случаев после выполнения указанных настроек перезагрузка ни гостевой, ни хостовой машины не требуется. Однако если что-то не работает, в первую очередь рекомендуется перезагрузить систему.

Протестировать работу Jumbo Frames можно с помощью простой команды ping, позволяющей определить что пакет большого размера может быть передан без дефрагментации:

где, флаг f — запрещает фрагментацию пакета, флаг –l задает размер пакета (8972 — на нашем стенде это максимальный размер пакета, передающийся без дефрагментации), second_jumbo_frame_server – имя/ip_адрес второго сервера с включенным Jumbo Frames.

Если ping отработал успешно – поздравляю, вы только что настроили Jumbo Frames для виртуальной машины на Hyper-V!

Настройка Jumbo Frames из Powershell

Указанные выше операции можно выполнить и с помощью всемогущего Powershell:

Следующая команда позволяет узнать включен ли Jumbo Frames для сетевого адаптера с именем Ethernet:

Если команда возвращает Disables (RegistryValue 1514), этоозначает, что Jumbo Frames в настоящий момент не включен, и используется стандартный размер MTU – 1514 байт.

Задаем увеличенный размер пакета для данного интерфейса:

Windows network jumbo frames

Jumbo frames are Ethernet frames with a payload greater than the standard mtu of 1500. Increasing the mtu size on a 1 GB network usually improves network performance and efficiency.The following PowerShell cmdlets will help display and check current jumbo frame values and edit them.The maximum value of a Jumbo frame on an Ethernet adapter varies depending on the network adapter brand.

I have a Windows Server 2012R2 with four NICs in a team. After setting the Jumbo frame values at the individual NICs, they should be inherited by the NIC team adapter.The Advanced Properties of the NICs are displayed below:

The Get-NetAdapterAdvancedProperty -Name nic2 cmdlet displays the current Jumbo frame value of NIC2 in the team:

My attempt to set the Jumbo frame value on this NIC to 9014 failed, with the following error message “the value must be within the range 1500-9000” as indicated :

Set the new value to 9000:

Get-NetAdapterAdvancedProperty -Name nic2 -RegistryKeyword «*jumbopacket» | Set-NetAdapterAdvancedProperty -RegistryValue 9000

The new value is shown in the following screen shot:

I completed the same configuration on the remaining team NICs.To optimize performance on the network and take full advantage of this configuration, the next logical step in the process is to configure the corresponding Cisco switch port for Jumbo frames.

By default, the switch and it’s gigabit ports/interfaces are set to the standard 1500 mtu. As indicated in the following command :

L3Switch#sh system mtu

System MTU size is 1500 bytes
System Jumbo MTU size is 1500 bytes
Routing MTU size is 1500 bytes

This could also be verified by using the sh run command as shown below:

L3Switch#sh running-config
Building configuration.

Current configuration : 3666 bytes
!
version 12.2
no service pad
service timestamps debug datetime msec
service timestamps log datetime msec
service password-encryption
!
hostname L3Switch
!
boot-start-marker
boot-end-marker
!
enable secret 5 $1$w7It$7sxFdFRIbKR7zfDZeYJq2/
!
no aaa new-model
clock timezone CST -5
system mtu routing 1500

And the sh interfaces gigabitEthernet0/21 command for a specific interface:

L3Switch#sh interfaces gigabitEthernet0/21
GigabitEthernet0/21 is down, line protocol is down (notconnect)
Hardware is Gigabit Ethernet, address is 64d8.148e.8015 (bia 64d8.148e.8015)
MTU 1500 bytes, BW 10000 Kbit, DLY 1000 usec,
reliability 255/255, txload 1/255, rxload 1/255

Configure Jumbo Frame values on the Cisco Gigabit switch globally:

L3Switch#config t
Enter configuration commands, one per line. End with CNTL/Z.
L3Switch(config)#system mtu jum
L3Switch(config)#system mtu jumbo ?
Jumbo MTU size in bytes
L3Switch(config)#system mtu jumbo 9000 ?

L3Switch(config)#system mtu jumbo 9000
Changes to the system jumbo MTU will not take effect until the next reload is done
L3Switch(config)#^Z
L3Switch#
*Mar 1 00:23:12.967: %SYS-5-CONFIG_I: Configured from console by console
L3Switch#reload

System configuration has been modified. Save? [yes/no]: y
Building configuration.
[OK]
Proceed with reload? [confirm]

After reload, verify Jumbo Frame settings have taken effect:

L3Switch#sh system mtu

System MTU size is 1500 bytes
System Jumbo MTU size is 9000 bytes
Routing MTU size is 1500 bytes

Verify the settings for a specific interface:

L3Switch#sh interfaces gigabitEthernet0/21
GigabitEthernet0/21 is down, line protocol is down (notconnect)
Hardware is Gigabit Ethernet, address is 64d8.148e.8015 (bia 64d8.148e.8015)
MTU 9000 bytes, BW 10000 Kbit, DLY 1000 usec,
reliability 255/255, txload 1/255, rxload 1/255

Working Hard In IT

My view on IT from the trenches

Configuring Jumbo Frames with PowerShell in Windows Server 2012

During lab and test time with Windows Server 2012 Hyper-V some experimenting with PowerShell is needed to try and automate actions and settings. One of the thing we have been playing around with was how to enable and configure jumbo frames.

Many advanced features like Large Send Offload have commandlets of their own (Enable-NetAdapterLso etc.), but not all them and jumbo frames is one of the latter. For those advanced features you can use the NetAdapterAdvancedProperty commandlets (Network Adapter Cmdlets in Windows PowerShell). You can than set/enable those features via the registry keywords & values. Let’s say we want to enable jumbo frames on a virtual adapter named “ISCSI” in a VM.

To know what values to use you can run:

Get-NetAdapterAdvancedProperty -Name ISCSI

As you can see Jumbo Packet has a RegistryValue of 1514 and a DisplayValue of “Disabled”. You can also see that the RegistryKeyword to use to enable and configure jumbo frames is “*JumboPacket”. So to enable jumbo frames you run the following command:

Set-NetAdapterAdvancedProperty -Name “ISCSI” -RegistryKeyword “*JumboPacket” -Registryvalue 9014

The RegistryValue is set to 9014 and the DisplayValue is set to “9014 Bytes”, i.e. it’s enabled.

If you type in an disallowed value it will list the accepted values. Please note also that these can differ from NIC to NIC depending on what is supported. Some will only show 1514, 4088, some will show 1514, 4088, 9014.

Now to disable jumbo frames you just need to reset the RegistryValue back to 1514

Set-NetAdapterAdvancedProperty -Name “ISCSI” -RegistryKeyword “*JumboPacket” -Registryvalue 1514

The result of this command can be seen in the picture below. DisplayName Jumbo Packet has a DisplayValue of “Disabled” again.

Let’s say you want to enable jumbo frames on all network adapters in a host you can run this:

Get-NetAdapterAdvancedProperty -DisplayName “Jumbo Packet” | Set-NetAdapterAdvancedProperty –RegistryValue “9014 ”

Set-NetAdapterAdvancedProperty -Name * -RegistryKeyword “*JumboPacket” -Registryvalue 9014

I didn’t notice much difference in speed testing this with measure-command.

If you mess things up to much and you want to return all DisplayName settings to a well known status, i.e. the defaults you can run:

Reset-NetAdapterAdvancedProperty –Name SCSCI –DisplayName *

If you’ve just messed around with the jumbo frame settings run

Reset-NetAdapterAdvancedProperty -Name ISCSI –DisplayName “Jumbo Packet”

Or you can do the same for all network adapters:

Reset-NetAdapterAdvancedProperty –Name * –DisplayName “Jumbo Packet”

There you go, you’re well on your way doing the more advanced configurations of your network setup. Enjoy!

Windows network jumbo frames

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Answered by:

Question

Hello, I have a brand new HP server with 2 NICs.

I enabled jumbo frames on both NICs, and then added them into a NIC team.

I cant find whether the teamed NIC needs to also have jumbo frames enabled as well. I cant seem to find a way to enable them either.

Does this teamed nic in server 2012 R2 need to have jumbo frames enabled? How do I do this? How do I verify that jumbo frames is working.

Answers

>>I cant find whether the teamed NIC needs to also have jumbo frames enabled as well. I cant seem to find a way to enable them either.

As far as I know, teamed NIC inherits the MTU set from the NICs of the team.

Configuring on the physical NICs and you would get a team available of jumbo frames.

>>How do I verify that jumbo frames is working.

Run the command ping with -l Size flag.