lyngsie08
Contributor
Contributor

About VM network and vDS

Some months ago my company migrated all standard switches to a distributed switch (besides service console/vswif0). Today I took a thorough look into the vDS settings and found, that one of the hosts did not have it's VM Network (on vmnic1) registered in our hosts-file and thus shouldn't be able to receive an IP on our actual/physical network.

vDS is new to me, so I wonder how the VM's on this host connects to the VM network? The only vmnic on the host that actually have an IP on the network is the service console. Vmotion and NFS are on internal switches. Does the vDS route VM traffic through the service console if no specific VM network is found?

NB:

Looking in "Manage Physical Adapters" (under dVS configuration) the observed IP range is right as I write this, but earlier today I observed the range was 128.0.0.1 - 255.255.255.254. Might not be related to this or maybe it's a minor bug somehow. It always shows the right range for the vmnic1 under "Network Adapters".

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logiboy123
Expert
Expert

Can you post a screenshot of your vSwitch and dvSwitch configurations?

VM Network Port Groups do not require an IP address to be set in order for VM's to recieve an IP address. If you have VM's on this host then the host must be provisioning a VM Networking Port Group either from a vSwitch or dvSwitch with the same label as the other hosts in the cluster.

dvSwtiches do not route VM traffic through anything other then the VM Network Port Group they are defined from. So no your dvSwitch is not routing traffic via the service console.

A dvSwitch is very similar to a standard vSwitch with the following being a major exception; You define your dvSwitch once, and then apply this configuration to the hosts that you want to share this switch configuration. When you make a change on the dvSwitch, it changes the configuration on all hosts that this switch is connected to. Essentially this saves time when doing major changes to your entire infrastructure and/or when setting up a new host in the same cluster.

Host profiles work in a similar way. One thing I like to do to confirm that my hosts are set up the same is to pick a host that I define as my gold host and then I create a host profile from this. I apply this profile to the other hosts, put them into maintenance mode and apply the profile. Before the profile is applied, it lists all of the items that it will change as part of the process. If nothing is going to be changed, then you know you configurations are good across multiple hosts.

Regards,

Paul Kelly

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lyngsie08
Contributor
Contributor

Thanks for your reply.

I realize that I probably need to read up on vNetwork. All VM's are of course registered in DNS, so the VM Networking port group only needs to be connected to the network. In fact, the host in question might actually be the only host that is rightfully configured in DNS. Meaning that vmnic1 that is used on all hosts for VM networking doesn't need to be registered as long as it delivers a connection to the network. This sounds logical to me, but would like it to be confirmed Smiley Happy

I inserted screenshots of vSwitch and dvSwitch (for the single host in question).

11764_11764.png

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logiboy123
Expert
Expert

To answer your question; When you click on vmnic on the right hand side of the vDS switch configuration screen it will highlight the port groups on the left hand side that is being used by it. So click on each of the NIC's on the right hand side and you will be able to see which port groups have been assigned to use those uplink ports.

By default all NIC's on a vDS act as a trunk. You can specify port groups that cannot use specific NIC's by editing the load balancing settings on that port group.

Regards,

Paul Kelly

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lyngsie08
Contributor
Contributor

Thanks for clarifying. Didn't know NIC's on a vDS act as a trunk.

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