We help IT Professionals succeed at work.

Vmware Distributed Switch.

jskfan
jskfan asked
Vmware Distributed Switch.

If I understand Distributed Switch can be used for many ESX Host while Standard Switch is on single host only.
However, I would like to know what is the limit in number of ESX hosts can be added to a Distribution Switch. for instance let 's say there are 300 ESXi Hosts in the DataCenter, would all 300 hosts be on one Distribution Switch ? what is the recommended and best practice?

Thank you
Comment
Watch Question

Andrew Hancock (VMware vExpert / EE Fellow)VMware and Virtualization Consultant
Fellow 2018
Expert of the Year 2017
If I understand Distributed Switch can be used for many ESX Host while Standard Switch is on single host only.

That's not correct Standard and Distributed switches are functions of ALL hosts.

You would normally use Distributed switches when you start using larger environments, because it allows you to deploy the same configuration of switch DISTRIBUTED TO all Hosts in the Cluster, so all hosts have exactly the same network, apart from many other enterprise features, load balancing, LACP and many other functions that do not exist in Standard Switches.

With Standard Switches if you deploy to multiple ESXi hosts, you must ensure you have the same configuration, e.g. Virtual Machine Portgroups the same on all hosts, otherwise vMotion is going to fail.

1000 is the max for distributed switches.

With 300 hosts it would be wise and recommended to use Distributed Switch, but there are no VMweare police! that do not stop you doing standard switches per host.... but it's alot of work to maintain consistency across 300 hosts, but not impossible.

Author

Commented:
I thought Standard switches are by single Host  .. Example on HostA you can configure vSwitch1 , vSwitch2,, but  you cannot associate  the same vSwitch1 and vSwitch2 you created on HostA to HostB.
 
Alos, if I understand you comment above Distribution Switch can be by Cluster.. I mean you can have one Distribution Switch for all Hosts in the CLuster.

So if you have 2 Clusters , will you be able to configure Distribution Switch to all hosts in both clusters....? is it possible but not best practice or it is impossible ?

Thanks
Andrew Hancock (VMware vExpert / EE Fellow)VMware and Virtualization Consultant
Fellow 2018
Expert of the Year 2017
I thought Standard switches are by single Host  .. Example on HostA you can configure vSwitch1 , vSwitch2,, but  you cannot associate  the same vSwitch1 and vSwitch2 you created on HostA to HostB.

That is correct, but to say they are only Single Host is not accurate.

Alos, if I understand you comment above Distribution Switch can be by Cluster.. I mean you can have one Distribution Switch for all Hosts in the CLuster.

I was referring to, if you had many hosts, they would normally be in a cluster, but if you wish you can use Distributed Switches on single host! or two hosts, not in a cluster.

So if you have 2 Clusters , will you be able to configure Distribution Switch to all hosts in both clusters....? is it possible but not best practice or it is impossible ?

Possible, as you add distributed switches to a host. (hosts are in clusters).

Author

Commented:
you mean one Distribution Switch can span 2 Clusters ?
Andrew Hancock (VMware vExpert / EE Fellow)VMware and Virtualization Consultant
Fellow 2018
Expert of the Year 2017
You create a vDS and then you add it to Hosts or Clusters. (hence the Distributed function).

Author

Commented:
I understand that....

if we have 300 Hosts... can we put them in one CLuster , create one vDS and associate the hosts with vDS.

My point is when do you need to create separate Clusters, separate vDS ?
VMware and Virtualization Consultant
Fellow 2018
Expert of the Year 2017
if we have 300 Hosts... can we put them in one CLuster , create one vDS and associate the hosts with vDS.

Of course, you add 300 hosts to one cluster.

You can create a vDS and assign it to ALL the hosts in that Cluster.

and you can create another vDS and assign it to ALL hosts in another Cluster.

Some organisations like to have a vDS per Cluster, some have a vDS for all hosts. (in multiple clusters).

As for defining Clusters and defining vDS it's up to your design.

Normally before you design your vDS you work out what hosts you are going to use/add, and you also need to know their physical network interfaces because it makes a difference when you apply and add vDS to a host if it's missing uplinks!

So it helps if ALL hosts are the same, you've also got to ensure that all physical switch configuration is done and complete and working.

So usually you would have hosts and cluster design done, before you continue to vDS.

Author

Commented:
We'll come back to design later..
Thank you