Stale IP address allocation in IP Pool after device decommission - VMware NSX

Products

• VMware NSX

Issue/Introduction

• Within NSX-T IP Pools will show the incorrect number of allocated addresses 
• The incorrectly listed addresses in use are devices that have since been removed
• This issue can lead to IP Pool exhaustion prematurely
• The number of endpoints that consume IP address from the IP Pool is the same, but the number of allocated IPs is increasing.

Environment

VMware NSX-T Data Center3.x
VMware NSX 4.x

Cause

The IP Pool will not update the allocation if a device or virtual machine is removed via unconventional methods

Resolution

Use the NSX API to remove the orphaned entries via the steps below:

1. List the available IP pools and their Object IDs:
   
   GET https://<NSX_MANAGER_IP>/api/v1/pools/ip-pools
   
   
2. Identify the object ID of the pool and copy it for the next step:
   
   SAMPLE OUTPUT:
   
   

   "check_overlap_with_existing_pools": false,
   
   "ip_address_type": "IPV4",
   
   "resource_type": "IpPool",
   
   "id": "####-####-####-####-####",  <======= Object ID
   
   "display_name": "<Name of IP Pool>",           <======= Name of IP Pool
   
   "description": "<User Provided Description>",
   
   "_system_owned": true,
   
   "_create_time": 000000000001,
   
   "_create_user": "system",
   
   "_last_modified_time": 0000000000002,
   
   "_last_modified_user": "system",
   
   "_protection": "NOT_PROTECTED",

3. List the allocated IP Addresses within the pool, use the ID from step 2. Take note of the addresses that need to be removed:
   
   GET https://<NSX_MANAGER_IP>/api/v1/pools/ip-pools/########-####-####-####-############/allocations
   
   
4. Using the POST function issue the following API Call along with the sample field below within the body of the POST API call to release the orphaned entry:
   
   POST https://<NSX_MANAGER_IP>/api/v1/pools/ip-pools/########-####-####-####-############?action=RELEASE
   
   Body of POST:
   

   {
    
   "allocation_id": "<IP Address to be Removed>"
    
   }

   


5. Once the entry has been removed, it may take up to 5 minutes for NSX to sync and show the updated allocation, run the command from step 3 to confirm the entry is removed

Additional Information

NSX API Guide