vCHA Dedicate Network Related Inquiries

[Tedfl]

Hi,

When configuring vcha, the network requirements stated in the document are as follows:

1) The HA network should be on a different subnet from the management network.

2) Network latency between nodes should be less than 10ms.

3) When configuring the node, you should not specify the gateway to the HA network.

I have several questions.

1. Does vmware recommend physically separating the ha network from the management network? ? Or is it just an option?

2. When the management network and the ha network are not physically separated, is it a problem if only the port group is separately used in the same standard switch?

3. If the management network and the HA network are not physically separated, is there a difference between using and not using VLANs? Is the traffic load difference due to broadcast?

4. Is the replication traffic between the active node and the passive node/witness node massive?

5. Why not specify a gateway for the HA network?

[scott28tt]

@Tedfl 

Moderator: Moved to vCenter Discussions - vCenter Server Heartbeat is an end of life product and not related to vCenter HA 

[vxprthu]

HI,

I'm not sure i can answer all of your questions without knowing your environment and requirements about failover.

In general, physical separation is not necessary, a different (than mgmt network) VLAN will be fine. All 3 nodes should be in the same VLAN therefore gateway is not required.
The amount of the traffic is on your environment as the database replication is synced (using the postgresql own db replication), while the file replication is async. How much data will be replicated is unique to every system (based on changes).

You can find explanation for different use cases here: https://blogs.vmware.com/vsphere/2018/04/vcenter-high-availability-deep-dive-part-1.html 

[Tedfl]

Hi,

Thank you for answer.

One more question.

When configuring an HA network, must it be configured with vlan?

[vxprthu]

Hey,

In that case if you have standard switches and just separate with portgroups without vlans, the traffic will not be separated from other port groups. Which is not the recommendation.

Separation from management network is recommended, which could be either vlans or physical separation. 

But if you don't have other option, just create a different portgroup, probably will be fine, I didn't test it anywhere. If you have option for any network separation, use it.

[JinuV]

please refer the attached document