![](http://www.electricmonk.org.uk/wp-content/uploads/2019/07/Network-Port-150x150.png)
Using Curl to test port conectivity from vCenter
Curl is available in the VMware vCenter Server Appliance command line interface. This small blog provides a simple example of using Curl to simulate a telnet connection to test port connectivity
To test port connectivity in VMware vCenter Server Appliance:
- Log in as root user through the VMware vCenter Server Appliance console.
- Run this command on the vCenter Server Appliance:
curl -v telnet://target ip address:port number
Example of testing port connectivity
All vCenter servers must have access to the UMDS server on port 80 (http)
The below screen-print shows a working curl test from a vCenter to a Windows UMDS Server on IP address 10.124.74.65 over port 80.
![](http://www.electricmonk.org.uk/wp-content/uploads/2019/08/Curlcheck.png)
Using Netcat to test port connectivity from hosts
The telnet command is not available in any versions of ESXi and, therefore, you must use netcat (nc) to confirm connectivity to a TCP port on a remote host. The syntax of the nc command is:
nc -z <destination-ip> <destination-port>
![](http://www.electricmonk.org.uk/wp-content/uploads/2019/08/Portcheck-1.png)
Thanks it helped me