vSphere HA agent on this host could not reach isolation address: 172.20.10.2

[BiswarajPattan]

Hi team,

Good day,

I am getting an alert saying vSphere HA agent on this host could not reach isolation address 172.xxx on ESXi Host summary tab. I have assigned  default gateway IP 172.20.10.2. on ESXi host1 . When i am trying to ping default gateway, I am getting request time out. This is the Lab environment built in VMware Workstation. In VMware workstation Network Adapter 1 is configured as host-only.  My Laptop has connected to WIFI internet. how to fix this error

[maksym007]

how many ESXi hosts are in LAB? 

Check the IP addresses at all of them. There is no rocket science. Everything is very simple and straightforward. 

I assume you have small misconfiguration 

[ptarnawski · Accepted solution]

The error message "vSphere HA agent on this host could not reach isolation address 172.xxx" indicates that the vSphere HA agent on the ESXi host cannot reach the isolation address. The isolation address is the IP address of the network that is used to isolate failed hosts from the cluster.

In your case, the isolation address is 172.20.10.2. You have assigned this IP address as the default gateway on the ESXi host, but you are getting a "request time out" error when you try to ping the default gateway. This indicates that there is a problem with the network configuration on the ESXi host.

The most likely cause of the problem is that the host-only network adapter in VMware Workstation is not configured correctly. The host-only network adapter is used to connect the ESXi host to the vCenter Server. If the host-only network adapter is not configured correctly, the ESXi host will not be able to communicate with the vCenter Server or the other hosts in the cluster.

To fix the problem, you need to make sure that the host-only network adapter is configured correctly. You can do this by following these steps:

1. Open VMware Workstation.
2. Click on the "Edit" menu and select "Preferences".
3. Click on the "Network" tab.
4. Select the "Host-only Adapter" and click on the "Edit" button.
5. Make sure that the "IP Address" and "Subnet Mask" fields are correct.
6. Click on the "OK" button.

Once you have configured the host-only network adapter correctly, you should be able to ping the default gateway and the other hosts in the cluster. If you are still getting an error, you may need to restart the ESXi host.

Here are some additional troubleshooting steps that you can try:

• Check the network cables and make sure that they are properly connected.
• Restart the VMware Workstation service.
• Restart the ESXi host.

[BiswarajPattan]

@ptarnawski  Thanks for the confirmation and your valuable suggestion. Now its working . I am Happy😀

Thanks again !!