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tfryar
Contributor
Contributor

"Management traffic" option for port?

What does the "managment traffic" option for a kernel port actually do? I've seen this question asked all over, but never answered?

I can still use vSphere client to get into a host when this is not checked. Since there are other options for FT or VMotion traffic...and it's not used for the client.....what does checking "management traffic" under port options actually do?

Thanks!

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VMmatty
Virtuoso
Virtuoso

The management traffic option on a VMkernel port is used to allow management access to an ESXi host. You use that IP for connectivity to the vSphere Client, vCenter, etc. By default ESXi has a VMkernel port called "Management network" that has the "management traffic" option selected.

You can assign multiple IP addresses to be used for management traffic. Some folks do this as an alternate means of accessing the server should the first one go down.

If you've ever used Classic ESX before, the "management traffic" option on a VMkernel port group is the same as having a Service Console port group.

Matt | http://www.thelowercasew.com | @mattliebowitz
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AndreTheGiant
Immortal
Immortal

The management vmkernel port on ESXi is quite the same of a Service Console port on ESX.

Andre

Andrew | http://about.me/amauro | http://vinfrastructure.it/ | @Andrea_Mauro
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tfryar
Contributor
Contributor

Actually, by default, the "management traffic" option is not selected for the autocreated "management network"? At least not in my version here (ESXi 4.x). This is a mystery to me...if vmware created that network for the purpose of management traffic, why is the checkbox not selected by default?

If it's console traffic, how can I still get to it when "management traffic" is OFF?

Odd......

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VMmatty
Virtuoso
Virtuoso

I'm surprised that the option for management traffic wasn't checked by default. I've never seen that happen by default. You need that selected to manage the host so maybe it is enabled on a different VMkernel port?

Matt | http://www.thelowercasew.com | @mattliebowitz
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Chemi
Contributor
Contributor

I don't have it either in my ESXi 4.1 - it still allows me to connect it to the Vsphere client or Vcenter

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makruger
Contributor
Contributor

If I were to venture a guess, I would say this option is used only for assigning priority for traffic on a distributed virtual switch. I suspect the same applies to "Fault Tolerance Logging". Or in other words...it's like QOS or something.

On a standard switch, these options probably serves no purpose, unlike "vMotion" which (according to the ESXi configuration guide), enables a port to advertise itself for vMotion traffic.

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rickardnobel
Champion
Champion

Michael wrote:

On a standard switch, these options probably serves no purpose, unlike "vMotion" which (according to the ESXi configuration guide), enables a port to advertise itself for vMotion traffic.

What is strange is that if the management network and vMotion network share the same IP subnet (but separated vSwitches / VMNICs for the vmkernels) the vMotion traffic will use the management nic instead. That is, IP routing has higher priority than the checkboxes..

My VMware blog: www.rickardnobel.se
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makruger
Contributor
Contributor

Good to know.

Fortunately, I am not using the same subnet for vMotion. But if using a single subnet, perhaps it would be a good idea to separate the traffic using VLAN tagging. Seems like that should settle the matter.

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rickardnobel
Champion
Champion

Michael wrote:

But if using a single subnet, perhaps it would be a good idea to separate the traffic using VLAN tagging. Seems like that should settle the matter.

If using the same IP subnet for both management and vMotion then you could not have a different VLAN on vMotion, so it would be necessary to do as you already have: two different IP networks (which should have their own VLAN too.)

My VMware blog: www.rickardnobel.se
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fatbobsufc
Contributor
Contributor

Sorry to revive an old thread but stumbled on this by googling.  Looks like this question never received a definitive answer, and checking the VMware documentation I couldn't find an answer either...

In the current (small) setup I am working though I have their vmotion and management on the same VMKernel interface (yeah I know you're not supposed to) and although the enable vmotion option is checked, the management traffic option isn't.  I've always noticed this and always 'wondered'.  Now I am redoing the scripted installs for ESXi 5 I thought it would be a good time to double check.

I am going with to go with the idea that this only matters if you have a second VMKernel ip.  If there is only one VMkernel IP then by default that will also be the interface used for management traffic.

Satisfies my tiny brain Smiley Happy

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CedricAnto
VMware Employee
VMware Employee

Management network is the primary network interface that uses a VMkernel TCP/IP stack to facilitate host connectivity and management. It can additionally handle system traffic such as vMotion, iSCSI, NFS, FCoE, Fault Tolerance, vSAN.

Management traffic: Enables a vmkernel interface to be used by vSphere HA

Cedric http://in.linkedin.com/in/cedricrajendran/ http://virtualknightz.com/
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