Vcenter HA error same network/26

[Caramon1980]

Hello!!

I have Vcenter deployed with the management IP at 10.10.1.31/26 and I want to deploy HA.
The addresses for the active, passive and witness node would be the following:

Active: 10.10.1.80/26
Passive: 10.10.1.81/26
Witness: 10.10.1.82/26

I left the gateway blank.

Once HA is created, when I do a manual failover, the cluster never remains stable, it is always changing the active node every 5 minutes.

Is it possible to do it like this, or should I do it in another subnet, for example, 10.10.2.x?

Best regards!

[markey165 · Accepted solution]

@Caramon1980 - Unless i'm mistaken, those IP addresses aren't in the same subnet? If you're using VLANs and telling the VMs they're on one network when they're actually on another, that could be your issue.

A /26 consists of 64 addresses, and splits a /24 into 4 blocks, where the last octet is 0-63, 64-127, 128-191 and 192-255 (excluding network and broadcast addresses). So the addresses you've quoted (ie .31 and .81/82/83) would reside in different subnets.

Here's a screenshot of our working VCHA config from when we used to run it, in case its useful. We used 2 Subnets/VLANs. One for management, and one dedicated to the HA network. From memory I think we used a /29 for HA (which gives you 6 addresses) as we only needed 3 IPs.

HTH 😊

[Caramon1980]

Thank you very much for your help.!!

We will try to do as you mentioned and I will keep you informed of the result.

[markey165]

@Caramon1980 - No problem, let us know how it goes as i'm interested to know the fix (and it will be useful for others 😊)

[Caramon1980 · Accepted solution]

The solution given is correct, in addition, the NTP ports were not open and it was also necessary to open them for it to work.

[markey165]

Good news @Caramon1980 - Thanks for updating the thread, and glad it helped guide you in the right direction 😊