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infusednz
Enthusiast
Enthusiast

Distributed Switch between hosts

Hi Guys,

I have two hosts and a distributed switch. Everything works fine, apart from when I move one host to another server. It can no longer communicate with the other hosts in that port group.

What is needed for cross-host communication using distributed switch?

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15 Replies
rickardnobel
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infusednz wrote:

Hi Guys,

I have two hosts and a distributed switch. Everything works fine, apart from when I move one host to another server. It can no longer communicate with the other hosts in that port group.

What is needed for cross-host communication using distributed switch?

You use the word host both for the ESXi host and the guest operating systems, but I assume that you lose connectivity between one guest and another guest after moving it to another host?

The issue is likely at the physical switch configuration. How many uplinks do you have from the Distributed vSwitch from each host? Do you have VLANs defined on the virtual port groups?

My VMware blog: www.rickardnobel.se
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infusednz
Enthusiast
Enthusiast

What's the ideal way to configure the distributed switch? I was basically configuring two port groups per customer. A private and public group. On the public I would have vlanx with just one of the hosts or a vShield Edge in it. On the private I would have vlany with the local addressing of the vms.

Would this be a good way to configure it?

My private port groups have no vlans yet as there's no communication across the switch. I knew this would be the issue, just wanted to confirm.

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rickardnobel
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infusednz wrote:

My private port groups have no vlans yet as there's no communication across the switch. I knew this would be the issue, just wanted to confirm.

How is your physical switch setup and how many uplinks do you have from your Distributed vSwitch on each host? The communication between guests on different host is something that should not be an issue, and could in your case be caused by the switch set up on the physical side or possible from the portgroup settings.

Could you post a screenshot of the Distributed vSwitch and the private VM portgroups?

My VMware blog: www.rickardnobel.se
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infusednz
Enthusiast
Enthusiast

Please see the attached image

Capture.PNG

Connects in to Juniper switch. Each server has 4 uplinks. You can guess from the uplinks what each is used for.

I don't have any vlans on the private at the moment as I'm just testing. I will assign these shortly. However, that shouldn't be an issue when the switch is set to pass all vlans.

Also, ignore that vmotion only has 1 nick. Vmotion is currently being done across vmtraffic.

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rickardnobel
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Champion

Could you also show the NIC teaming settings for the private portgroup? (Teaming and Failover)

My VMware blog: www.rickardnobel.se
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infusednz
Enthusiast
Enthusiast

They are all using VM Traffic1 and 2.

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Josh26
Virtuoso
Virtuoso

infusednz wrote:

They are all using VM Traffic1 and 2.

But each of these are on the same vSwitch? I don't think this is doing what you think it's doing.

I'm guessing the uplinks on VM traffic 1 is meant to pass different VLANs to VM traffic 2 from your description. But an uplink will pass every VLAN that is on its vswitch. If the goal is for a set of "VM traffic 1" virtual machines to uplink to different physical ports, they should be on a different vSwitch to the "VM traffic 2" virtual machines.

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rickardnobel
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infusednz wrote:

They are all using VM Traffic1 and 2.

Could you post a screenshot of the Teaming and Failover tab, showing the active / standby / unused settings for the portgroup?

As Josh has mentioned depending on your exact setup and goals then this might not be the best (or even working way) to set it up.

My VMware blog: www.rickardnobel.se
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infusednz
Enthusiast
Enthusiast

Sure

Capture.PNG

Public ones are the same.

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rickardnobel
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Champion

Do you know that these interfaces ("vm traffic") from the two hosts connects into four ports on your physical switch with the exact same setup? Same VLAN settings (for access / untagged), same security settings, same Spanning Tree configuration and similiar?

My VMware blog: www.rickardnobel.se
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Josh26
Virtuoso
Virtuoso

So you have two uplinks, and they are each a team of two physical ports?

Is there a reason you don't use one team of four ports? This may help answer the bigger issue..

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infusednz
Enthusiast
Enthusiast

This was a design error in the beginning, we are going to use all the 4 ports once we have some time to reconfigure.

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Josh26
Virtuoso
Virtuoso

I suspect you are in the middle of correcting design errors that may relate to your issue.

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infusednz
Enthusiast
Enthusiast

So, in the end we will have public and private port group with different vlans for each. Each port group will have 4 uplinks. This should work correct?

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rickardnobel
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infusednz wrote:

So, in the end we will have public and private port group with different vlans for each. Each port group will have 4 uplinks. This should work correct?

If you have one or several vmnics connected to the same Distributed vSwitch and portgroup, connected to physical switches identical configured on the attaching ports then it should work correct.

My VMware blog: www.rickardnobel.se
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