There is a need to change the IPAM/Subnet associated with a VN. However this VN had VM's, VPG and is extended to LR.

When tries to change the IPAM the job fails.

We try to change VN allocation pool to excluding an IP address dedicated to a machine as the target subnet is short. This address is currently used by the service. managed by contrail tool

Method used for this change, is to recreate a new VN as the pool allocation in VN can not be changed directly

Detailed WorkFlow

1- create new VN on contrail

2- replace OL VN by the New VN for VPG and LR

However the Job Fails!!!!!!

The recommendation is to follow the below steps

1. Delete all associated objects from VN a) VPG b) VMI c) LogicalRouters.
2. Delete the IPAM/VN
3. Create a new VN and IPAM
4. Rebuild the a) VPG b) VMI c) LogicalRouters back.

IPAM is the basic block on VN and is referenced multiple nodes. Any deletion/modification without cleaning up the linked references can be problematic.