Can not connect with Azure Bastion

Question

Can not connect with Azure Bastion

BMcInnis 21

Hello I am a student and new to networking. For a project I need to connect to a virtual machine and I am using Azure. Specifically Bastion because my Windows 10 Home does not have Remote Desktop. I created a free tier of a virtual machine and went to Bastion but it said the "To associate a virtual network with a Bastion, it must contain a subnet with name AzureBastionSubnet with prefix of at least /27." So I went to "manage subnet configuration" and tried to change the /24 to /27 but it said it said "failed to update" subnet is in use and can not be changed. Please help. Sorry if this is a newbie question.

Andreas Baumgarten 67,716 Reputation points MVP

2020-11-30T19:12:05.44+00:00
Your VM is connected to a Virtual Network and a Subnet in this Virtual Network.
You need to create a new Subnet in the Virtual Network with the name AzureBastionSubnet and a subnet mask of /27 minimum. A /24 subnet is fine as well. The only requirement is the name AzureBastionSubnet.

For instance:

Virtual Network: 10.0.0.0/16

VMsubnet: 10.0.0.0/24 (VM is connected with this subnet)

AzureBastionSubnet: 10.0.1.0/24 or 10.0.1.0/27

(If the reply was helpful please don't forget to upvote and/or accept as answer, thank you)

Regards
Andreas Baumgarten
BMcInnis 21 Reputation points

2020-11-30T20:34:47.177+00:00

Under the AzureBastionSubnet the name "default" is 10.1.1.0/24 and I was not able to connect to the virtual machine with Bastion which is why I posted this question. I assume I had to change the mask /24 to /27.
Andreas Baumgarten 67,716 Reputation points MVP

2020-11-30T20:41:43.467+00:00

Could you please post your configuration of Virtual Network and Subnets (or screenshots).
This makes it easier to find a solution.

(If the reply was helpful please don't forget to upvote and/or accept as answer, thank you)

Regards
Andreas Baumgarten
BMcInnis 21 Reputation points

2020-11-30T21:22:48.37+00:00

Here you go let me know if you need more information for steps on what I need to do

https://i.imgur.com/uSypXka.png

https://i.imgur.com/1SyJsdM.png

https://i.imgur.com/aDDf9Iz.png

https://i.imgur.com/VblET7Y.png
Andreas Baumgarten 67,716 Reputation points MVP

2020-11-30T21:49:32.733+00:00

The default subnet is 10.1.1.0/24. And the address space for the Virtual Network is 10.1.1.0/24.
This is why you can't add another subnet. But this is required for the Bastion Host.

(If the reply was helpful please don't forget to upvote and/or accept as answer, thank you)

Regards
Andreas Baumgarten
BMcInnis 21 Reputation points

2020-11-30T21:56:06.427+00:00

Here is the image of the address space

https://i.imgur.com/b0Hyan1.png
GitaraniSharma-MSFT 29,976 Reputation points Microsoft Employee

2020-12-03T10:46:42.85+00:00

Hello @BMcInnis ,

Just checking in to see if @Andreas Baumgarten 's answer helped. If this answers your query, please don’t forget to click "Accept the answer" and Up-Vote for the same, which might be beneficial to other community members reading this thread. And, if you have any further query do let us know.
GitaraniSharma-MSFT 29,976 Reputation points Microsoft Employee

2020-12-08T08:32:19.013+00:00

Hello @BMcInnis ,

Could you please provide an update on this post?

Kindly let us know if the below answers helped or you need further assistance on this issue.

----------------------------------------------------------------------------------------------------------------

Please don’t forget to close the thread by clicking "Accept the answer" wherever the information provided helps you, as this can be beneficial to other community members.

Andreas Baumgarten 67,716 Reputation points MVP

2020-11-30T19:12:05.44+00:00

Your VM is connected to a Virtual Network and a Subnet in this Virtual Network.
You need to create a new Subnet in the Virtual Network with the name AzureBastionSubnet and a subnet mask of /27 minimum. A /24 subnet is fine as well. The only requirement is the name AzureBastionSubnet.

For instance:

Virtual Network: 10.0.0.0/16

VMsubnet: 10.0.0.0/24 (VM is connected with this subnet)

AzureBastionSubnet: 10.0.1.0/24 or 10.0.1.0/27

(If the reply was helpful please don't forget to upvote and/or accept as answer, thank you)

Regards
Andreas Baumgarten
BMcInnis 21 Reputation points

2020-11-30T20:34:47.177+00:00

Under the AzureBastionSubnet the name "default" is 10.1.1.0/24 and I was not able to connect to the virtual machine with Bastion which is why I posted this question. I assume I had to change the mask /24 to /27.
Andreas Baumgarten 67,716 Reputation points MVP

2020-11-30T20:41:43.467+00:00

Could you please post your configuration of Virtual Network and Subnets (or screenshots).
This makes it easier to find a solution.

(If the reply was helpful please don't forget to upvote and/or accept as answer, thank you)

Regards
Andreas Baumgarten
BMcInnis 21 Reputation points

2020-11-30T21:22:48.37+00:00

Here you go let me know if you need more information for steps on what I need to do

https://i.imgur.com/uSypXka.png

https://i.imgur.com/1SyJsdM.png

https://i.imgur.com/aDDf9Iz.png

https://i.imgur.com/VblET7Y.png
Andreas Baumgarten 67,716 Reputation points MVP

2020-11-30T21:49:32.733+00:00

The default subnet is 10.1.1.0/24. And the address space for the Virtual Network is 10.1.1.0/24.
This is why you can't add another subnet. But this is required for the Bastion Host.

(If the reply was helpful please don't forget to upvote and/or accept as answer, thank you)

Regards
Andreas Baumgarten
BMcInnis 21 Reputation points

2020-11-30T21:56:06.427+00:00

Here is the image of the address space

https://i.imgur.com/b0Hyan1.png
GitaraniSharma-MSFT 29,976 Reputation points Microsoft Employee

2020-12-03T10:46:42.85+00:00

Hello @BMcInnis ,

Just checking in to see if @Andreas Baumgarten 's answer helped. If this answers your query, please don’t forget to click "Accept the answer" and Up-Vote for the same, which might be beneficial to other community members reading this thread. And, if you have any further query do let us know.
GitaraniSharma-MSFT 29,976 Reputation points Microsoft Employee

2020-12-08T08:32:19.013+00:00

Hello @BMcInnis ,

Could you please provide an update on this post?

Kindly let us know if the below answers helped or you need further assistance on this issue.

----------------------------------------------------------------------------------------------------------------

Please don’t forget to close the thread by clicking "Accept the answer" wherever the information provided helps you, as this can be beneficial to other community members.

Answer 1

Andreas Baumgarten 67,716 MVP

At the end it should look like this:

Virtual Network Address Space

Subnets

----------

(If the reply was helpful please don't forget to upvote and/or accept as answer, thank you)

Regards
Andreas Baumgarten

Andreas Baumgarten 67,716 Reputation points MVP

2020-11-30T21:55:55.73+00:00

Based on your screenshots you can do the following:

Modify the address space of the vNet:
From 10.1.1.0/24
To: 10.1.0.0/16

After the address space of the vNet is increased you can add another subnet:
Name of the Subnet must be: AzureBastionSubnet
Subnet Address Space: 10.1.2.0/24

After this is done you should be able to deploy the Bastion Host using the now existing AzureBastionSubnet subnet

(If the reply was helpful please don't forget to upvote and/or accept as answer, thank you)

Regards
Andreas Baumgarten
BMcInnis 21 Reputation points

2020-11-30T22:53:36.503+00:00

Okay you are a wizard for getting me this far. Will make sure to give all the upvotes when this is over. I managed to create the Bastion. However one problem is I am failing to connect because

"The target machine is either unreachable or the username or password is incorrect"

when I made sure to write it down and the username is even showing up under SSH. So I guess I will try to just reset password and hopefully I get in. Thank you so far though and if you have any comments on that let me know, thanks.

Answer 2

Andreas Baumgarten 67,716 MVP

Everything is working now?

If so, it would be great if you could mark the answer with "accept as answer". This will help others with their search for answers in Q&A.

Regards
Andreas Baumgarten

BMcInnis 21 Reputation points

2020-12-08T18:29:06.243+00:00

Oh yeah its working thanks.

Answer 3

Samuel Agunloye 1

Fortunately, i googled my way into here and boom! @Andreas Baumgarten did answered the question. This is to confirm that your answers are correct and upvoted them to be Ok

Can not connect with Azure Bastion

2 additional answers

Activity