In my Azure subscription I have 2 peered VNETs. VNET1 has address space 10.16.0.0/16 and VNET2 has 10.250.21.0/24. I have chosen the space addresses so that they were completely different. Peering works given that a VM in VNET1 can ping a VM in VNET2.
However, from VNET 1 I can't access an App Service deployed in VNET2. I tried to access the App Service using the IP address and the private DNS name.
Network Security Groups in both VNETs seem to be fine. I'm able to change them so that basic network diagnostics work (for instance, ping).
Any suggestions please?
EDIT 1 + SOLUTION
I can say that it's solved. After peering the virtual networks, I had to "link the private DNS zones". I had a few issues with the address spaces, but nothing that a terraform destroy/apply couldn't solve.
I tried to reproduce the same in my environment and got the results like below:
I have created a vnet peering with two different space address like below:
Created a app service with premium p1v2 and added outbound traffic vnet integration and added a private endpoint like below:
Then, I created a vm and connect through bastion:
When I try to verify in command prompt using nslookup got result successfully like below:
Related
While creating the Virtual network gateway and selecting the vnet, it says the VNet is "in use".
VNET address space is 10.0.0.0/16
Any idea why I'm getting this error?
I created a new subnet and it has no devices connected to it.
The connected devices are not on GatewaySubnet.
I reproduce your scenario and it is working fine for me.
Below Point Should be notice before creating VNET Gateway
Gateway subnet address range: This field only appears if your VNet doesn't have a gateway subnet. It's best to specify /27 or larger (/26,/25 etc.).
Please check the same for Gateway Subnet address range from this MS doc: Tutorial - Create and manage a VPN gateway: Azure portal - Azure VPN Gateway | Microsoft Docs
Why do we have to create a new subnet or add the app service to an empty subnet in our vnet?
I don't understand the reasoning since I'm trying to use my app service (function app) as a reverse proxy to access the resources in the vnet.
By default, the Azure function is a PaaS as the other Azure Platform-as-a-Services that have inbound and outbound traffic over the Internet. We can host our applications without the need to worry about the maintenance of the servers and their operating systems.
To use Azure Functions to connect to resources in an Azure virtual network, we can use the VNet integration feature. To use this feature, we need to create a subnet in the virtual network for your function app to use. VNet Integration must be configured to use an empty subnet. It doesn't matter that your functions use a different subnet than your VM. The virtual network automatically routes traffic between the two subnets. Read Connect your function app to the virtual network
The extra empty subnet is used to hosting your app instance. To let the app instance outbound traffic work like from a VNet, Azure mounts NICs with assigned private IP addresses in that subnet. With VNet integration, your function app is connected to both the internet and your virtual network.
For more information, you may read How regional VNet Integration works and How gateway-required VNet Integration works
For an app to access resources in a Virtual Network, it needs to be either part of that network, or use a VPN gateway, which in turn can be used access resources inside the Virtual Network.
App Services provides 2 methods to communicate with resources in the Virtual Network:
Regional VNet Integration
Gateway-Required VNet Integration
With Regional VNet Integration, the infrastructure allocates a private IP interface on the VM that is hosting your Web App. This interface is allocated an IP address from the integrated subnets address prefix. This interface is later used to communicate with the VNet hosted resources. This is in a way similar to how IaaS VM work, however the limitation of this interface is that it can be only used for making outbound connections.
This way, if the ASP is configured to scale out to multiple VM's then each VM is allocated a corresponding private IP interface. However, the allocation of these IP address is limited to the subnets Address prefix. Nancy has already included this in her post. App Services have overlapped recycling so during scale up/maintenance, the App Service Plan may run on twice the number of VM's to ensure minimal downtime. However this also means, that the Integrated Subnet should have sufficient addresses available, so that these allocations can happen.
The IP Address of this interface is exposed via the environment variable WEBSITE_PRIVATE_IP. Here is a screenshot of my Kudu Console
If your site is running on multiple instances, then you can use the Instance menu to toggle through the instances.
With Gateway-required VNet Integration, there is a pre-requisite of provisioning a Virtual Network route-based gateway configured with an SSTP point-to-site VPN. In this case, the VM's hosting the Web App download the VPN package on the respective VM's to setup a VPN, and this is used to connect to the resources in the Virtual Network.
Even here, you can use the WEBSITE_PRIVATE_IP environment variable to see the IP Address used by the VPN client on the App Service VM.
HTH,
Kaushal
We have managed AKS Cluster and it has a few applications PODS. In the same subscription, we have a few servers in the different Resource Group and different VNET. We have a requirement to happen a communication between these two VNET's. I have configured vnet peering between two VNET's but we can see that the communication is not happening.
When I add a rule like "Allow port 443 from all networks" on to the NSG of Virtual machines then everything works fine.
Troubleshooting steps are done.
VNET Peering
Got an API Server IP Address from the "kubeconfig" file and added in the NSG of VM's in a diff RG.
But did not resolve an issue. Could you please help me to fix the issue.
AKS Resources are behind the Internal Load Balancer, so peering did not help. I had to use the Public IP Address provisioned during the AKS Creation process in the NSG. After adding PIP(Available in MC_rg-*** resource group) everything started working.
I would suggest to try connecting the VNET's through VPN gateways .
From an Azure virtual network, connecting to another virtual network is essentially the same as connecting to an on premises network via site-to-site (S2S) VPN.
You will need to go through the below listed steps :
Create VNetA and VNetB and the Corresponding Local Networks.
Create the Dynamic Routing VPN Gateways for each virtual network.
Connect the VPN Gateways.
Please find the referred document for implementing the same solution I have mentioned above .
For more information on difference of vnet peering and vnet gateway you can refer this document.
I have created one Web app on Azure portal and its integrated with subnet under specific VNET.
Now, when I am trying to do telnet to one of my organisation's internal relay server IP from my web app its not getting connected. The request is going from web app's APIPA address range not from subnet's address range. I checked the IP as well of the web app using ifconfig and I found out that its taking from APIPA address range not from subnet one.
Any idea what steps do I need to take so that web app will take IP from subnet address range of the VNET not from APIPA address range.
Thanks in advance.
After my validation, when the app service on Linux is integrated with a virtual network. There is an extra NIC binding to the app service. It's IP address from APIPA address range. It looks like a design behavior as the app service on Linux is running in a standard Docker Container, read here. Also, for a normal app service is a multi-tenant environment, you can not get a dedicated IP address unless you are using a dedicated environment---ASE, read here.
Furthermore, from how regional VNet Integration works, you will see the app service integrated with a vNet is not the same as a VM from a VNet.
Regional VNet Integration works by mounting virtual interfaces with
addresses in the delegated subnet. Because the from address is in your
VNet, it can access most things in or through your VNet like a VM in
your VNet would. The networking implementation is different than
running a VM in your VNet. That's why some networking features aren't
yet available for this feature.
In this case, if you wan assign a private IP address for app service, you can use Azure Private Endpoint with web apps(Preview). Read this blog for more details.
Azure Private Endpoint provides private IP address access by using a
network interface controller (NIC) attached to a virtual network
subnet for an Azure web app, allowing access from an on-premise VPN or
ExpressRoute. Implementing an endpoint effectively blocks the public
inbound access. This technology is very similar to an internal App
Service Environment (ASE) but much cheaper.
I have two virtual networks (classic) in Azure, and I need to be able to ssh between vms on these networks. I have followed the instructions here (https://azure.microsoft.com/en-us/blog/vnet-to-vnet-connecting-virtual-networks-in-azure-across-different-regions/), and successfully connected the networks. However, when I try and ping vm1 on vnet1 and vm2 on vnet2 the request times out, so it looks like vm1 cannot see vm2. Are there any further steps I need to take to allow communication? Shouldn't they be able to see each other's private IP addresses?
That's a pretty loaded question, but I think there is a better walk through for you to have a look at:
Configure a VNet-to-VNet connection in the Azure Classic Portal
or
Configure a VNet-to-VNet connection for virtual networks in the same subscription by using Azure Resource Manager and PowerShell
Pick your poison... I've verified both of these work as intended if you follow the steps carefully.