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GSS344
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VM's lose network connectivitiy if I move to 2nd nic on host

Hi,

I have a 2 nic esxi 5.5 server. If I move my vm network to my 2nd nic (retaining my vm's IP configuration), they drop off the network (yellow exclamation mark in Windows/lose internet connection).

Is there something in esxi I have ommitted to do?

Please advise.

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rcporto
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Hum... the problem may be on the physical switch... an Cisco feature called Port Security can disable a physical switch port if the same MAC address appear on different ports... and since the VM was working on the 1st vSwitch, the MAC address of this virtual machine was associated to physical switch port connected to vmnic used for the 1st vSwitch, but when you change this VM to the 2nd vSwitch the physical switch detects the MAC address trying associate with vmnic used for the 2nd vSwitch and than disable the physical switch port where the vmnic1 is connected.

The solution is ask your hosting provider if they are really using Port Security and disable it.

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Richardson Porto
Senior Infrastructure Specialist
LinkedIn: http://linkedin.com/in/richardsonporto

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rcporto
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Please, post a print screen of your vSphere ESXi host network configuration to let us understand your network configuration first.

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Richardson Porto
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LinkedIn: http://linkedin.com/in/richardsonporto
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GSS344
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Sure. Please see the attached screenshot. My network setup is very simple for now. You will notice the red x on the second NIC. I do not know why that is. It may be a vsphere issue, or the physical server, or my server hosting provider?

My host/vmkernel is on a public ip with a default gateway, pretty standard (I am going to change this to a private IP that goes through my firewall's private IP as the gw, but VPN issues prevent that).

My VMs (which I access via vsphere client for now), are on private ip's and go through the private ip of the fw as the gateway.

Thanks

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rcporto
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Seems like the physical NIC associated with vmnic1 is disconnected... take a look Network Adapters on Hardware panel... this will show as Disconnected and you may need make further investigation why this interface is disconnected, and since this host are on a hosting provider my suggestion is ask the hosting provider if both network interface are supposed to be connected.

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Richardson Porto
Senior Infrastructure Specialist
LinkedIn: http://linkedin.com/in/richardsonporto
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GSS344
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Thanks, Richardson.

The confusing thing is that prior to creating a vm network on the 2nd, the network adapters shows the first 2 NICs as connected? I say first 2 as there are a total of 4, but prior to any changes (and even now), the last 2 are disconnected which is intentional by the host.

Surely if the 2nd nic was not connected, before I made the 2nd vm network, it would show as disconnected in network adapters?

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GSS344
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Interestingly when I change a test server back to "VM Network", the 2nd switch looks fine.

Please see my 2 attachments.

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rcporto
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Hum... the problem may be on the physical switch... an Cisco feature called Port Security can disable a physical switch port if the same MAC address appear on different ports... and since the VM was working on the 1st vSwitch, the MAC address of this virtual machine was associated to physical switch port connected to vmnic used for the 1st vSwitch, but when you change this VM to the 2nd vSwitch the physical switch detects the MAC address trying associate with vmnic used for the 2nd vSwitch and than disable the physical switch port where the vmnic1 is connected.

The solution is ask your hosting provider if they are really using Port Security and disable it.

---

Richardson Porto
Senior Infrastructure Specialist
LinkedIn: http://linkedin.com/in/richardsonporto
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GSS344
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Hi,

You were on the right lines, the 2nd nic is not connected to the internet and is for private server-to-server communication. Thanks for the assistance.

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rcporto
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You're welcome and don't forget to award points for helpful or correct answers.

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Richardson Porto
Senior Infrastructure Specialist
LinkedIn: http://linkedin.com/in/richardsonporto
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