Why can't anyone connect to my VM through port 43594

Question

Why can't anyone connect to my VM through port 43594

Socom 0

I recently just activatet my VM and I went into my Firewall and made a new rule allowing incoming connections through port 43594 TCP & UDP but upon testing am still not able to connect. I am clearly missing something but I can't figure out what it is. Any help would be greatly appreciated.

GitaraniSharma-MSFT 50,096 Reputation points Microsoft Employee Moderator

2023-06-19T10:48:39.0066667+00:00
Hello @Socom ,

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

I understand that you would like to know why no one is able to connect to your VM through port 43594.

The issue you are facing could be due to one or more of the below reasons:

There are NSGs at both VM NIC and subnet level which could be blocking the port. Check NSGs at both NIC and subnet level and if there are NSGs at both levels, make sure the port is allowed on both NSGs.

There is a firewall blocking the port on the VM itself (windows firewall etc.). Refer: https://learn.microsoft.com/en-us/troubleshoot/azure/virtual-machines/guest-os-firewall-blocking-inbound-traffic

There is nothing listening on port 43594 on your VM's OS.

You should check your service first. Make sure there is a service listening on port 43594. To find specified open port, use find switch. For example, to find if the port 43594 is open or not, do netstat -an |find /i "43594" command. The service should listen on 0.0.0.0.

Could you please check the above and let us know the status?

Regards,

Gita
GitaraniSharma-MSFT 50,096 Reputation points Microsoft Employee Moderator

2023-06-21T10:29:59.3333333+00:00
Hello @Socom ,

Could you please provide an update on this post?

If you've already checked all the above steps and still facing an issue, we can connect offline for a much closer look. Please send an email with subject line “Attn: gishar | Why can't anyone connect to my VM through port 43594” to AzCommunity[at]Microsoft[dot]com with the following details, I will follow-up with you.

Reference this Q&A thread

Your Azure Subscription ID

Affected Azure VM name

Note: Do not share any PII data as a public comment.

We will post a summarized answer once the issue is resolved.

Regards,

Gita
GitaraniSharma-MSFT 50,096 Reputation points Microsoft Employee Moderator

2023-06-22T16:12:41.4033333+00:00

@Socom , could you please provide an update on this post? If you are still facing the issue, please send us an email as requested in my previous comment. Thanks!
GitaraniSharma-MSFT 50,096 Reputation points Microsoft Employee Moderator

2023-06-26T10:29:30.2366667+00:00

@Socom , do you have any new updates on this post? Please send us an email if the issue persists.

2 answers

Your answer

GitaraniSharma-MSFT 50,096 Reputation points Microsoft Employee Moderator

2023-06-19T10:48:39.0066667+00:00

Hello @Socom ,

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

I understand that you would like to know why no one is able to connect to your VM through port 43594.

The issue you are facing could be due to one or more of the below reasons:

There are NSGs at both VM NIC and subnet level which could be blocking the port. Check NSGs at both NIC and subnet level and if there are NSGs at both levels, make sure the port is allowed on both NSGs.

There is a firewall blocking the port on the VM itself (windows firewall etc.). Refer: https://learn.microsoft.com/en-us/troubleshoot/azure/virtual-machines/guest-os-firewall-blocking-inbound-traffic

There is nothing listening on port 43594 on your VM's OS.

You should check your service first. Make sure there is a service listening on port 43594. To find specified open port, use find switch. For example, to find if the port 43594 is open or not, do netstat -an |find /i "43594" command. The service should listen on 0.0.0.0.

Could you please check the above and let us know the status?

Regards,

Gita
GitaraniSharma-MSFT 50,096 Reputation points Microsoft Employee Moderator

2023-06-21T10:29:59.3333333+00:00

Hello @Socom ,

Could you please provide an update on this post?

If you've already checked all the above steps and still facing an issue, we can connect offline for a much closer look. Please send an email with subject line “Attn: gishar | Why can't anyone connect to my VM through port 43594” to AzCommunity[at]Microsoft[dot]com with the following details, I will follow-up with you.

Reference this Q&A thread

Your Azure Subscription ID

Affected Azure VM name

Note: Do not share any PII data as a public comment.

We will post a summarized answer once the issue is resolved.

Regards,

Gita
GitaraniSharma-MSFT 50,096 Reputation points Microsoft Employee Moderator

2023-06-22T16:12:41.4033333+00:00

@Socom , could you please provide an update on this post? If you are still facing the issue, please send us an email as requested in my previous comment. Thanks!
GitaraniSharma-MSFT 50,096 Reputation points Microsoft Employee Moderator

2023-06-26T10:29:30.2366667+00:00

@Socom , do you have any new updates on this post? Please send us an email if the issue persists.

Answer 1

Manu Philip 20,206 MVP Volunteer Moderator

First place to check is at Effective security rules from Network settings to see the external connection on port 43594 is working or not. Make necessary changes so that the same port is not blocked for outbound connections.

From the VM, do a telnet to the port.

telnet localhost 43594

Telnet ok status means that the port is listening and no issues in the VM configuration

Then it could be an issue with ISP also. The following url is an online tool to check the open ports. Use your public IP and port to test it remotely

https://www.yougetsignal.com/tools/open-ports/

If it looks blocked, I guess ISP is blocking the port and need their support

--please don't forget to upvote and Accept as answer if the reply is helpful--

Socom 0 Reputation points

2023-06-19T06:49:51.1833333+00:00

Effective security rules reflect inbound connections to port 43594 through both, UDP/TCP protocols, were created and are currently enabled. I've already tested the new rules through numerous port checking websites and all have confirmed port is closed.

I don't understand how Azure's ISP is blocking this and I have tried to get in contact with support but to no avail which is why I brought myself to create this help thread. All of the above were checked and changed to the assumed proper way but have failed. I don't know what else to do. I don't know what else to do. I really do appreciate your quick response but I'm still in the same position.
Manu Philip 20,206 Reputation points MVP Volunteer Moderator

2023-06-19T08:36:52.41+00:00

I see that, you have verified the inbound port status. However, have you seen the outbound connection is also unblocked?

I have indicated to see if the ISP who provides internet connection has some rules to disable the port so that, when you try accessing the port from your computer, you feels it is blocked.

You may also test this by creating a different vm in the same network to test this by bypassing the isp factor
GitaraniSharma-MSFT 50,096 Reputation points Microsoft Employee Moderator

2023-06-19T10:49:48.86+00:00

Hello @Socom ,

Hope you are doing great. I am just following up with you to understand more about your feedback on this thread.

We noticed your feedback that the above answer was not helpful with below feedback:

"Effective security rules reflect inbound connections to port 43594 through both, UDP/TCP protocols, were created and are currently enabled. I've already tested the new rules through numerous port checking websites and all have confirmed port is closed."

Thank you for taking time to share your feedback.

I have added some comments under your question. Please take a look and let us if you need further assistance on this issue.

We are here to help you and strive to make your experience better and greatly value your feedback.

We look forward to hearing from you.

Regards,

Gita

Answer 2

msrini-MSFT 9,291 Microsoft Employee

Hi, Can you try to execute netstat -ano and check if the port which you wanted to connect is listening ? Then check your guest os firewall - Windows firewall or IP tables to see if that port is allowed or not.

Socom 0 Reputation points

2023-06-19T19:24:50.67+00:00

I hate to be a bother but none of this worked.. It simply isn't allowing connections through a properly listening port. Is there someone I can talk to or a number to call? Otherwise i'm completely stuck and will have to end my subscription and consider the past 3 days as time wasted.
msrini-MSFT 9,291 Reputation points Microsoft Employee

2023-06-20T06:49:51.96+00:00

Can you drop an email to msrini@microsoft.com with an teams meeting invite for early PST hours? I will try to assist you over a call.

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Why can't anyone connect to my VM through port 43594

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