Issues with creating new service engines in Avi if a static IP pool is configured for the management network but DHCP is enabled

Products

• VMware Avi Load Balancer

Issue/Introduction

• When Avi is integrated with a vCenter or NSX-T cloud, and configured with both a static IP pool for the management network and the 'Enable DHCP' option in the cloud/network configuration, it can lead to IP assignment issues.
• In this configuration, Service Engine (SE) virtual machines may not receive a management IP address, which can prevent successful SE creation.
• This can be confirmed by checking if an IP address has been assigned to the service engine VM on vCenter.
• A symptom of this problem is that the Service Engine creation process may become stuck in a state indicating 'Waiting for Service Engine to connect to controller'.

Environment

• VMware vCenter
• VMware NSX-T

Cause

This problem occurs when Avi is set up with a defined range of static IP addresses for its management network, and at the same time, the option to use DHCP is also enabled in the cloud or network settings, but the underlying network environment is not actually providing DHCP IP addresses.

Resolution

Steps to resolve this issue:

1. If a healthy Service Engine exists: Migrate any affected virtual services to a functioning Service Engine. If no other Service Engines are currently operational, proceed to the next step.
2. If no healthy Service Engine exists: Temporarily disable the affected virtual service(s).
3. Remove the down Service Engine: Delete the Service Engine virtual machine that did not receive an IP address and failed to create successfully.
4. Disable DHCP in Cloud Settings: Navigate to the cloud configuration within Avi and ensure the 'Enable DHCP' option is unchecked. Save your changes.
5. Disable DHCP in Management Network Settings: Similarly, navigate to the management network configuration within Avi and ensure the 'Enable DHCP' option is also unchecked. Save your changes.
6. Trigger New Service Engine Creation: Re-enable the disabled virtual service. This should trigger a new service engine creation.