Symptoms

In the NSX-T UI dashboard, the NSX transport node shows "disconnect" status for the NSX-T controller. On the failing ESXi node, after running the command below, it shows a disconnected status for the NSX controller. nsxcli -c get controllers When you run the below command for testing the Transmission Control Protocol (TCP) port 1235, some NSX managers are not reachable. nc -z nsx-syslog.log: 2023-12-13T05:59:04.213Z nsx-proxy[2103782]: NSX 2103782 - [nsx@6876 comp="nsx-esx" subcomp="nsx-proxy" s2comp="nsx-rpc" tid="2103786" level="WARNING"] RpcConnection[1210 Connecting to ssl://NSX manager IP :1234 0] Couldn't connect to ssl://NSX manager IP :1234 (error: 110-Connection timed out) 2023-12-13T05:59:05.768Z nsx-proxy[2103782]: NSX 2103782 - [nsx@6876 comp="nsx-esx" subcomp="nsx-proxy" s2comp="nsx-net" tid="2103786" level="WARNING"] StreamConnection[1209 Connecting to ssl://NSX manager IP :1235 sid:1209] Couldn't connect to 'ssl://NSX manager IP :1235' (error: 110-Connection timed out)

Cause

Communications issue between NSX Manager and NSX-ProxyNSX Manager communicates with NSX-Proxy through port 1234.The central control plane (CCP) communicates with NSX-Proxy through port 1235.In the NSX-T environment, the NSX-T Manager also contains the NSX-T Controller component. NSX-T Controllers control the virtual networks and overlay transport tunnels. The controllers are responsible for the programmatic deployment of virtual networks across the entire NSX-T architecture.

Resolution

Troubleshooting steps: Review the nsx-syslog.log of the ESXi node. Check if there are any errors between the node and NSX-T manager. Use to test communications from the ESXi node to all NSX-T manager TCP ports 1234 and 1235. nc -z If there are issues, check the customer's firewall, to see if they block NSX-related traffic.

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