When setting up the Backend pools of an Azure Application Gateway, I want to set a specific VM in the pool.
This VM is in another VNet, and I've set up peering between the App Gateway's VNet and the VM's VNet.
Still, when I choose Virtual Machine as the target type of the Backend pool, the list is empty and I don't see any VM.
What's the problem? Am I missing something?
It seems that you only could see VMs in the same VNet as the application gateway located when you select the virtual machine as the target type of the backend pool.
If you have VNet peering, you can just add the internal IP of the VM to target the backend pool.
A backend pool routes request to backend servers, which serve the request. Backend pools can contain:
NICs
Virtual machine scale sets
Public IP addresses
Internal IP addresses
FQDN
Multitenant backends (such as App Service)
If you use internal IPs as backend pool members, you must use virtual
network peering or a VPN gateway. Virtual network peering is supported
and beneficial for load-balancing traffic in other virtual networks.
Reference: https://learn.microsoft.com/en-us/azure/application-gateway/application-gateway-components#backend-pools
Related
We deploy to Azure app services and to ensure secure traffic between each service they are configured with out bound traffic on a virtual network subnet. Each app service must have it's own subnet, which is understandable, but to allow the app services to communicate we are having to add inbound ip restrictions for each subnet, on each app service.
As all the subnets for all the app services within an environment are on the same virtual network we were expecting the traffic to route between the subnets. In that way by connecting each app service to an out bound subnet and allowing traffic back in on that subnet it would also allow traffic from the other subnets of the virtual network.
I've read here Azure: Routing between subnets a response that state "Azure routes traffic between all subnets within a virtual network, by default. You can create your own routes to override Azure's default routing." but that does not appear to be happening for us.
Is there a setting we need to change or a route that must be added to allow us to have a single inbound rule from the virtual network that allows all traffic from all subnets of the virtual network.
We are splitting our process into micro app services but this is making security of inter-app traffic complex as each time we add an app service we must update all others with an additional inbound rule before it can communicate.
We also have a similar issue with managing access to the azure sql database where we have connected the sql to a subnet in the virtual network but traffic from the app services cannot access over that subnet.
Any advice please?
I have two virtual machines in azure VNet (IP adresses 10.1.0.4 and 10.1.0.5), and one machine connected to VNet via VPN Gateway (IP 10.3.0.2). Is is possible to create a load balancing in internal load balancer to redirect UPD traffic to VPN connected machine?
Azure Load Balancer supports virtual machines or virtual machine scale sets as it's backend pool endpoints along with addition of instances via network interface or IP addresses. However, a backend pool configured by IP address has the following limitation:
The backend resources must be in the same virtual network as the load balancer.
Reference : https://learn.microsoft.com/en-us/azure/load-balancer/backend-pool-management#limitations
So, you cannot add a VPN connected on-premise machine in the backend pool of the load balancer. There is an active feature request for this and it is under review by the load balancer product group team. You can upvote this feature request in the below forum for future improvements:
https://feedback.azure.com/d365community/idea/49c222f6-8726-ec11-b6e6-000d3a4f0789
I have created a Virtual Network next to its subnet and integrated it into three service applications and created the rule on the firewall of my SQL Azure server.
Everything is in the same Azure subscription and region
I need to know if it is enough to direct all the traffic between these instances through the virtual network or do I need to configure some other aspect.
And how can I query the data traffic to verify that the virtual network is being used?
Azure Virtual Network (VNets) allows to place Azure resources in a non-internet-routable network.
https://learn.microsoft.com/en-us/azure/architecture/example-scenario/private-web-app/private-web-app#architecture
Using Azure App Service regional VNet Integration, the web app connects to Azure through an AppSvcSubnet delegated subnet in an Azure Virtual Network.
Virtual Network only routes traffic and is otherwise empty, but other subnets and workloads could also run in the Virtual Network.
The App Service and Private Link subnets could be in separate peered Virtual Networks, for example as part of a hub-and-spoke network configuration. For regional VNet Integration, the peered Virtual Networks must be located in the same Azure region.
Azure Private Link sets up a private endpoint for the Azure SQL database in the PrivateLinkSubnet of the Virtual Network.
The web app connects to the SQL Database private endpoint through the PrivateLinkSubnet of the Virtual Network.
The database firewall allows only traffic coming from the PrivateLinkSubnet to connect, making the database inaccessible from the public internet.
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
I have two peered VNETs in Azure and I also have an Application Gateway in one of them. I have a couple VMs inside both VNETs and I want to access the Application Gateway from the VMs by its private IP (which is set up). This works from the VNET that the gateway resides in but I can't access it from the other peered network. I can access all the VMs between the networks by their private IPs no problem. What can I be missing? (I am not really that familiar with networking, so it can be something basic...).
Thank you for any suggestion!
You can check if the two peered virtual networks are located in a different region.
If you are using a Global Vnet peering(Vnet to Vnet region is different), there are some limitations that you can not use Global Vnet peering to communicate with VIPs of load balancers in another region. Application Gateway is actually a layer-7 load balancer.
Resources in one virtual network cannot communicate with the IP
address of an Azure internal load balancer in the peered virtual
network. The load balancer and the resources that communicate with it
must be in the same virtual network.
References: How to setup Global VNet peering in Azure
APIM is a service based on Azure Load balancer. For Stv1 APIM Azure uses Basic Load balancer which does not allow traffic via global peering.
[Refer this][1]
In order to facilitate traffic via global peering need to use stv2 APIM.[Refer this][2]
[1]: https://learn.microsoft.com/en-us/azure/virtual-network/virtual-network-manage-peering?tabs=peering-portal#requirements-and-constraints
[2]: https://learn.microsoft.com/en-us/azure/api-management/virtual-network-concepts?tabs=stv1#network-resource-requirements