NSX Edge deployment fails during precheck "Validate IP Address Conflicts. Error occurred while performing the validation: sendto() failed (Host is down)"

Products

• VMware SDDC Manager

Issue/Introduction

Any failed precheck test can prevent an edge deployment from validating. If validation is failed the deployment will rollback and the edge in deployment will be deleted.

Cause

Any precheck failure can trigger this behavior. A common cause is conflict with an existing IP. In these cases you will see messaging similar to the example below in NSX edge deployment logs. https://knowledge.broadcom.com/external/article/376813/troubleshooting-nsx-installation-operati.html gives a breakdown on deployment related logging for NSX components.

"Validate IP Address Conflicts. Error occurred while performing the validation: sendto() failed (Host is down)"

Resolution

Check ARP tables for conflicting IP address.

Find MAC address associated with the conflicting IP and change the conflicting IP on that component.

In cases where DHCP assignment is being used, you can also exclude the conflicting IP from the DHCP scope.