I have an Internal application gateway configured in Azure. There is one virtual machine in the back end pool of application gateway which hosts the application. That is accessible via Intranet only.
I want the IP address of my internal application gateway to be associated to a domain name for my website?? How can i achieve this?
If you want to use a domain name, that means the application gateway needs to have a public IP address. In the gateway settings in the Azure portal, you can add a public IP address to the frontend configuration.
Looks like you already managed to put the backend of the gateway on the virtual network, that's good.
Next, you want to create a listener on the ports you need, for example 80 or 443. This is also done on the gateway configuration in the portal.
Finally, to use a domain name, you need to take the public IP address and put it in an A-record for the domain name. This would probably be in a config page with your service provider.
Related
I have the following situation:
If I deploy an application (Deployment, Service and Ingress) in my kubernetes cluster, my ingress deployment is being automatically added to my application gateway (I am using the Azure Application Gateway Ingress Controller; https://azure.github.io/application-gateway-kubernetes-ingress/annotations/ ). So far so good.
That means that my application can be reached via my application gateway via https://my-app-gateway-public-ip/myAppPath/. Also, I have an additional private DNS zone which makes my app accessible via https://dns-name/myAppPath.
Additionally, we have an AADDS in combination with a Bastion Service. Deployed some virtual machines and the virtual machines use the DNS resolver of the AADDS (for authentication against the AAD).
The problem is: If I am outside of the cloud, I can nslookup the dns or can access the site via the ip, but I cannot do that with my virtual machines. My DNS server (within the AADDS) is unable to resolve the dns or accessing the ip. I am wondering what the issue is.
The bastion and AADDS are in different subscriptions and therefore different virtual networks. I established already a peering between those virtual networks (or the authentication between the AADDS and the VMs wouldn't work).
The kubernetes cluster and the application gateway are also in a different subscription, but no peering has been done so far.
Are there any hints what I could be missing?
Kind regards
• Since, you are using a Bastion gateway server to connect to the VMs hosted in your subscription, the Bastion gateway server must be having a public IP address through which then the registered underlying VMs can be connected to via private links created in the private DNS zones associated with a particular virtual network in a subnet and an assigned private IP address and a FQDN accordingly. Thus, if you want to access the application website hosted behind the application gateway, then you will have to create a conditional forwarder in the DNS zone in AADDS to redirect the internal requests from the VMs hosted within a virtual network to the public IP address of the website hosted behind the application gateway
• Thus, a conditional forwarder forwards the DNS resolution requests for a particular resource hosted on the public internet for which the DNS host resolution is not found or done in that DNS zone which usually serves or fulfils the requests related to internal environment. As a result, when a VM configured with a private IP is registered as a host in the internal DNS zone queries the public IP or FQDN associated with the application’s website, the DNS requests are forwarded to the public internet through the conditional forwarder and then the results are displayed in the VM’s browser for the application’s webpage. Thus, the VMs don’t need to have internet access but the DNS server should have or should forward the requests through the Internet proxy server accordingly to reach the internet.
For more information on creating conditional forwarder in AADDS, kindly refer to the below link: -
https://learn.microsoft.com/en-us/azure/active-directory-domain-services/manage-dns#create-conditional-forwarders
I'm trying to deploy my application on Azure. Currently, I have an application gateway deployed in one subnet s1, and in the backend pool I have Linux VMs. As per the requirement, I cannot use any public ip so, I'm using only private ip on Application Gateway. Since we need the internet connection at the time of deploying application, I tried attaching NSG to the Application Gateway's subnet with inbound "Internet" allowed. When I attached the NSG to application gateway subnet, the backend health showed as unhealthy with error:
"Cannot connect to server. Check whether any NSG/UDR/Firewall is blocking access to server. Check if application is running on correct port."
I tried to add rules specified in MSFT's document https://learn.microsoft.com/en-us/azure/application-gateway/configuration-overview#allow-application-gateway-access-to-a-few-source-ips but its not helpful. So my questions are:
Is there anything more I need to add to NSG on application gateway's subnet.
Is it a good strategy to allow internet access using the inbound rule on NSG? (Inbound rule -> service tag -> Internet). Is there any other way I can have internet access just at the time of deployment? PS: I'm not allowed to use public IP at all.
Many thanks!
You can deploy Application Gateway with Public IP and Private IP. All you need to do is to create the listener with the private Frontend IP and leave the Public IP as such.
Since Public IP is not attached with any of the listener, no one will be able to access your site from Internet via Public IP of your Application Gateway.
When AppGW needs to initiate outbound to Internet, it uses that Public IP.
Note: You cannot have only Private IP as Frontend in V2 deployment and you can deploy Application Gateway with only Private Frontend IP in V1 SKU.
My health probe fails with a 403 as soon as I apply whitelisting to the App Service configured in the backend pool (I whitelist the IP that's assigned to the application gateway. IP is a standard tier and static.
Has anyone else been seeing this issue before? I was under the impression that I could whitelist the public IP assigned to the application gateway on the App Service so access is only possible from the Application Gateway endpoint.
The health probe is successful when I remove the whitelisting. So I'm sure it has something to do with that.
According to the document,
If the backend pool:
Is a public endpoint, the application gateway uses its frontend public
IP to reach the server. If there isn't a frontend public IP address,
one is assigned for the outbound external connectivity.
Contains an internally resolvable FQDN or a private IP address, the application gateway routes the request to the backend server by using
its instance private IP addresses.
Contains an external endpoint or an externally resolvable FQDN, the
application gateway routes the request to the backend server by using
its frontend public IP address. The DNS resolution is based on a
private DNS zone or custom DNS server, if configured, or it uses the
default Azure-provided DNS. If there isn't a frontend public IP
address, one is assigned for the outbound external connectivity.
Thus, you may use an internally resolvable FQDN or a private IP address of the backend app service in the backend pool.
In this case, you could change to use the default Azure app service hostname like webappname.azurewebsites.net or whitelist the internal app gateway subnet (where the application gateway instance private IP address) in the access restrictions of app service.
I'm migrating asp.net services that used to exist on a physical server on-premise to Azure. However they need to reach some web-services (SOAP) that will not be migrated to azure yet. These have a public IP but I need to set the hostname in order for IIS to properly redirect the requests to the correct service as there are several on the same server. Is there any way to create some sort of DNS-server in azure that is only available for the services created in azure that can resolve to the public IP-address outside of azure? (We have used the hosts file on the servers to achieve this previously)
I tried using the private DNS Zones, but as I've understood it they can only point to other azure services within the same vnet (correct me if I'm wrong). I've also tried creating a dnsmasq docker container. However, as this is running in a Linux container, it seems that I cannot put it in the same vnet as the asp.net app services. Thus I am unable to retrieve a private IP-address that these services can use to reach the DNS server.
In my understanding it is now possible to use Azure DNS Private Zones if you want.
You would need to use regional vnet integration to point your app's traffic to a vnet that is connected to the Private Zone. You need the following settings as well, which mean that all outbound traffic from the Web App is routed through the integrated vnet first, and that the Azure default DNS server is used for DNS.
WEBSITE_DNS_SERVER with value 168.63.129.16
WEBSITE_VNET_ROUTE_ALL with value 1
https://learn.microsoft.com/en-us/azure/app-service/web-sites-integrate-with-vnet#azure-dns-private-zones
If you don't want to use Azure DNS Private Zones, I think you can achieve similar results by directing the Web App to use a specific DNS server. This can be done using WEBSITE_DNS_SERVER and WEBSITE_DNS_ALT_SERVER app settings (the values are the IP addresses of the servers you want to use).
This is the most authoritative public statement I can find about using these settings.
Go to the web app->settings->Application Settings-> App Settings
section
Add the following: (WEBSITE_NODE_DEFAULT) should already be
there.
a. WEBSITE_DNS_SERVER with value having the IP address of the
primary DNS server.
b. WEBSITE_ALT_DNS_SERVER (optional), with value
having the IP address of a second DNS server.
Then save the settings & restart webapp in portal.
Double check the web app can actually
connect to the DNS server: a. In kudu console, run: Nameresolver.exe
[hostname-to-lookup] [dns-server-to-use]
First argument should be the
hostname you are trying to look up, second argument is one of the DNS
servers from step 1) If this times out, there is an issue with how
your DNS servers are configured (firewalls, etc.)
https://github.com/MicrosoftDocs/azure-docs/issues/13927#issuecomment-416382230
If using these settings with a DNS server that is only accessible via private IP, you would need to use regional vnet integration again to connect to a vnet. If the DNS server is on-prem, you have to connect through the integrated vnet over VPN or ExpressRoute.
It's possible but not using the private DNS Zone.
According to Name resolution for resources in Azure virtual networks. For the scenario Name resolution from App Service Web Apps in one virtual network to VMs in a different virtual network, you need to use your own DNS servers forwarding queries between virtual networks for resolution by Azure (DNS proxy). See Name resolution using your own DNS server.
In this case, you only allow this azure web service could resolve the public IP address outside of Azure. You could enable virtual network integration for your web app, this restricts your web app access in a private network. Then you could deploy a DNS server in the same Vnet as the web app integrated VNet. You could create an A type record in your DNS zone to point to your service Public IP, then add the DNS server's IP address into the DNS server of the Integrated web app Vnet in the portal. If so, the web app could resolve this public IP via a custom DNS server.
Hope this could help you.
App Service IP Restriction for Application Gateway with WAF
I want to setup Application Gateway WAF in front of multi-tenant (non-ASE) App Service Web Apps.
I know this is possible now, according to official document.
For security, inbound traffic to Web Apps should be restricted to only allow requests for connection the application gateway Public IP. But I couldn't find the way to do it.
Idea 1. Using VNet integration:
It's not possible to using "App Service Vnet Integration" cause it's not possible to specify App gateway's VNet.
Moreover, in my understanding, VNet integration can't restrict inbound traffic.
Idea 2. Using IP Restriction config of App Service:
Application Gateway's Public IP Address can be configured as Dynamic one, Static IP Address can't be chosen.
So, I think it's not possible to specify Application Gateway's Public IP Address to IP Restriction config of App Service, cause configured IP is static but actual IP can be changed.
Any good idea?
The Application gateway IP address can change if the gateway is stopped and started by the customer.
So if you have not stop and start the application gateway, the IP address will not change.