Wrong or duplicate TEP IPs are shown on NSX UI

Products

• VMware NSX

Issue/Introduction

• DHCP is used for assigning TEP IPs. 'Use DHCP' is selected for IPv4 Assignment under Host switch configuration.
• ESXI hosts show wrong TEP IPs on the NSX UI.
• This wrong IP was previously provided to a different Host by DHCP server. So from the UI, it may look like multiple hosts have the same or duplicate TEP IP.
• There is no traffic impact. Tunnels seem to be working fine.
• The below command on ESX shows the correct IP:

esxcli network ip interface ipv4 address list

Above command does not show the wrong IP.

• vCenter UI is showing the correct IPs for VMK interfaces
• With below API call, the output also shows the correct IPs-
   GET https://<Manager VIP>/api/v1/fabric/nodes/<UUID of transport node>

Sample:

https://#.#.#.#/api/v1/fabric/nodes/##31e2e1-943e-4d7d-####-#############
{
    "os_type": "ESXI",
    "os_version": "7.0.3",
   "managed_by_server": "#.#.#.#",
   "discovered_node_id": "##########-#####-#####-####-#############:host-3432",
    "resource_type": "HostNode",
   "id": "###########-####-####-########-############",
   "display_name": "#################",
   "external_id": "###########-####-####-########-############",
   "fqdn": "#################",
    "ip_addresses": [
       "#.#.#.#"
    ],
    "discovered_ip_addresses": [
       "#.#.#.#",
       "#.#.#.#",
       "#.#.#.#"
    ],
    "_create_user": "admin",
    "_create_time": 1691577294206,
    "_last_modified_user": "admin",
    "_last_modified_time": 1691577294206,
    "_protection": "NOT_PROTECTED",
    "_revision": 0
}

At the above output under discovered_ip_addresses, the correct TEP IPs can be seen.

• So the wrong IP is only showing at NSX UI.
• Reboot of NSX Managers does not help.
• Checking with incognito/ private mode of browser/different browser does not help. Wrong TEP IP can still be seen on UI.

 

Environment

VMware NSX

 

Cause

This is due to a known issue. The handling for VTEP DHCP IP change propagation from opsagent to MP is missing in code. This is only seen during vtep’s DHCP IP change.

Resolution

This issue is resolved in VMware NSX 4.2.0, available at Broadcom downloads.

If you are having difficulty finding and downloading software, please review the Download Broadcom products and software KB.

Workaround

• The Workaround is to reconfigure TN with same configuration. Or,
• Alternatively you can call below re-sync API.
  
  API: POST https://<managerIP>/api/v1/transport-nodes/<tn-id>?action=resync_host_config
  
  
  

Additional Information

Impact:

This is a cosmetic problem. This issue does not have any impact on datapath.