question

84254000 avatar image
0 Votes"
84254000 asked ABDULWAHEED-1027 answered

I can not telnet to my open port on azure virtual server

I can not telnet to my open port on an azure virtual server.
I open port 100 on a server and he is listening,
But The client can not access it. There is no ping and no telnet.
What is the issuse?

azure-virtual-network
5 |1600 characters needed characters left characters exceeded

Up to 10 attachments (including images) can be used with a maximum of 3.0 MiB each and 30.0 MiB total.

GitaraniSharmaMSFT-4262 avatar image
0 Votes"
GitaraniSharmaMSFT-4262 answered

Hello @84254000 ,

Welcome to Microsoft Q&A Platform. Thank you for reaching out & hope you are doing well.

In order to telnet to an Azure VM on an open/listening port, you need to make sure that the particular port is allowed in the NSG (Network Security Group) of the VM NIC and it's subnet.
Please refer : https://docs.microsoft.com/en-us/azure/virtual-machines/windows/nsg-quickstart-portal

Make sure the port is not blocked by a denied rule in your NSG.

You may also refer to other connectivity issues in the below article:
https://docs.microsoft.com/en-us/azure/virtual-network/virtual-network-troubleshoot-connectivity-problem-between-vms

Kindly let us know if the above helps or you need further assistance on this issue.


Please "Accept the answer" if the information helped you. This will help us and others in the community as well.

5 |1600 characters needed characters left characters exceeded

Up to 10 attachments (including images) can be used with a maximum of 3.0 MiB each and 30.0 MiB total.

ABDULWAHEED-1027 avatar image
0 Votes"
ABDULWAHEED-1027 answered

Hi,

There can be three different issues.

1- Server itself is not listening on port 100. use netstat to find out.
2- Check policy priority in NSG. maybe it has a higher priority than the default deny policy.
3- Check if you have selected port types, like TCP, UDP, or any.

you can also use iperf or tcplisten to temporarily open ports on your server to test on different ports.

5 |1600 characters needed characters left characters exceeded

Up to 10 attachments (including images) can be used with a maximum of 3.0 MiB each and 30.0 MiB total.