how to test port 902 TCP/UDP communication between esxi host and vcsa

[tdubb123]

how do I test the communication between a esxi host and vcsa appliance make sure the ports are opened?

[msripada]

From ESXi ssh or shell -> nc -uz <VC FQDN/IP> port -> to test the udp 902 connectivity test to vcenter

From vCenter -> you can check using telnet

for VCSA shell or ssh -> curl -v telnet <ESXi host IP/FQDN>:port  - This can only be valid for TCP 902 and for udp, you need to do packet capture.

Another quick help is if the ESXi host disconnects from vCenter every 60 seconds- high chances of 902 udp blocked

Thanks,

MS

[daphnissov]

You can do a simple curl request to the FQDN/IP of the ESXi host on port 902. If the port is open, you should see something like

curl esx5.domain.com:902

220 VMware Authentication Daemon Version 1.10: SSL Required, ServerDaemonProtocol:SOAP, MKSDisplayProtocol:VNC , VMXARGS supported, NFCSSL supported/t

[tdubb123]

from the esxi host I did

nc -uv vcenterIP 902

and got no response

I dont have access to vcsa

[tdubb123]

so I need to open udp/TCP 902 from the host to vcsa?

or vice versa?

[daphnissov]

If you don't have access to vCSA then what exactly do you think you're going to test? vCSA doesn't listen on port 902.

[tdubb123]

i am checking connectovity from the esxi host and does not seem to respond on udp 902

nc -uv vcenterIP 902

[daphnissov]

As I just said, vCSA doesn't listen on port 902, so that check is going to fail. You need to check from vCSA -> ESXi over port 902.

[tdubb123]

so is it TCP/UDP 902 on the ESXi host that needs to be opened  between the vcsa and ESXi?

[daphnissov]

TCP/UDP 902 needs to be opened to all ESXi hosts from vCSA.

[tdubb123]

I did a curl from the vcsa to the esxi host and it responded

[tdubb123]

did a packet capture on thie host. I am seeing 902 UDP

[andvm]

@daphnissov - Shouldn't the VCSA expect to receive heartbeats from each host on TCP/UDP 902 at least once a minute (think threshold is different according to vcsa version)? (Otherwise the hosts will be marked as disconnected)

[vmkfix-SSA]

I followed the below article to get details.

https://vmkfix.blogspot.com/2023/02/test-communication-between-vcenter-and.html