I try to connect a application who is in a subnet sub_A to a postgresql database that have a private endpoint in the subnet sub_B and still fail to do it.
I do a lot of try and i am able to connect in the database from a VM in sub_B so i expect that the issue comes from sub_A but here is ma configuration i configure on the database server the vmnet rules for sub_A and sub_B.
I configure the both subnet with the service endpoints "Microsoft.Sql"
and when i try to connect in the database throught the private endpoint i still get the error
error: FATAL: Client from Azure Virtual Networks is not allowed to access the server using Private IP. Please make sure your Virtual Network is correctly configured.
can you help me and tell me what i missed?
In this case, make sure the DNS record is set correctly.
If you have an application hosting on the app services, you could enable VNet Integration and you need to add the following app settings to work with Azure DNS Private Zones.
WEBSITE_DNS_SERVER with value 168.63.129.16
WEBSITE_VNET_ROUTE_ALL with value 1
If you have an application hosting on Azure VM or VMs, you could compare the DNS records of VMs in subnet A with subnet B. From subnet A, you need to make sure you can resolve to the private IP address from PostgreSQL database FQDN. Between Subnet A and Subnet B should not be network blocked.
For example, From SubnetA, verify that the private link points to the PostgreSQL resource and the necessary resolution is happening.
C:\Users\azureadmin>nslookup demoprivatelinkserver.postgres.database.azure.com.
Server: UnKnown
Address: 168.63.129.16
Non-authoritative answer:
Name: demoprivatelinkserver.postgres.database.azure.com
Address: 10.1.3.4
For more information, you could read this blog or let me know if you need further help.
Related
I have configured an Azure VPN point to site connection to access my azure resources prtected by VNet from my local machine. I was able to access all other resources except Azure Search Service using VPN. For all the resoucres I added the GatewaySubnet under "Selected Networks" of Networking settings and also mentioned the corresponding resource's IP address as additional route in VNet Gateway.
But for azure search service I cannot add the GatewaySubnet under selected networks because search service allows only public IP address range to be added when selecting "Selected Networks".
I am getting below error when connecting to search service with VPN connected
A connection attempt failed because the connected party did not
properly respond after a period of time, or established connection
failed because connected host has failed to respond.
System.Private.CoreLib: A connection attempt failed because the
connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond.
Am I missing any setting? Can someone help me on this?
You don't need to add anything in the Azure Search Firewall, if you got "Selected Networks" as your firewall setting, it means that you have not yet created a private enpoint for Search, if your main goal is to connect privately from On premise to Search then this will be your first step.
https://learn.microsoft.com/en-us/azure/search/service-create-private-endpoint
After the private endpoint is created, make sure that your clients know how to resolve xxxx.search.windows.net to the private IP of the newly created private endpoint, once that's done, it would all be a matter of ensuring that the routing is setup correctly and your clients should then be able to connect.
At this time, the only way to access the search service privately is through private endpoint, as mentioned in this doc.
To create a private endpoint attached to the virtual network where the local machine VPN is part of. When you connect through VPN, the machine that you're connecting from would acquire a private IP from the virtual network.
-summarized the answer from comments.
I was missing setting up the DNS forwarder. The public addresses are returned by Azure public DNS. The private addresses are returned by DNS internal to Azure. This means that we want to use DNS internal to Azure when accessing resources over a VPN connection. And this internal DNS provided by Azure is outside of our VNet and so we have to explicitly forward that using our own DNS forwarder.
We must add a DNS server to the VNet if we want DNS support for P2S or S2S connections. We must stand up our own DNS Server, actually a forwarder, and add it to the VNG DNS server list. Azure does not provide any DNS server that is addressable from the VPN connection.
We used azure firewall as a DNS forwarder and now everything works with VPN connected.
I am trying to access resources that are secured behind private endpoint from a remote location using an Azure VPN Point-to-Site connection.
So far I have setup a conditional forwarder to send DNS requests to Azure's internal DNS IP address (168.63.129.16). With my setup I can resolve all my private endpoints using nslookup to their private IP addresses. I can also connect to services such as SQL server from my local machine (using SQL Server Management Studio in the case of SQL server).
The problem I am facing is that I can only access resources if I use a desktop client for a given service. If I try to do anything using the Azure Portal, I get an error stating that I cannot access resources using my Public IP address without adding it as an inbound IP address. Whilst this is certainly an option, I don't want to go down this road.
I am hoping there is an option where I can connect to private endpoint resources from Azure Portal whilst connected to my point-to-site VPN. Any ideas?
So far I have setup a conditional forwarder to send DNS requests toAzure's internal DNS IP address (168.63.129.16). With my setup I can resolve all my private endpoints using nslookup to their private IP addresses. I can also connect to services such as SQL server from my local machine (using SQL Server Management Studio in the case of SQL server.
AfAIK, the process which you are doing is correct, To fix this issue try to update the local host file on client desktop to deploy a recourse with private endpoint please refer this link for more in detail
By default when you create a Private Endpoint in the Azure Portal it will automatically lock out public access. Service Endpoints operate by adding routes to allow traffic out of the virtual network to reach the public endpoint of the service selected. If you are access resources error, update firewall rules to communicate with your Azure resources you really need to configure v-net traffic on the firewall settings
Next option is conditional forwarder, in your scenario the ble from every v-net, its public ip it won't overlap with any private ips, it available from inside of azure v-net unique to each
In conditional for forwarder, client asks the ip of a host like www.seraltos.com .The dns server looks to see the answer if knows, if not a lookup will done based on root servers or forwarder to find the ip address returns that to the client
For more information in detail, please refer below links:
Private Endpoints and DNS in Azure & Cannot access my own public IP
https://learn.microsoft.com/en-us/azure/storage/common/storage-private-endpoints
https://learn.microsoft.com/en-us/azure/private-link/manage-private-endpoint?tabs=manage-private-link-powershell
PROBLEM:
I'm able to connect to the Azure SQL Database using the private link from VM within the virtual network, but not from my pc trough virtual network gateway
In sqlserver1 firewall, I have denied public network access.
From MyVM in the myvnet, I'm able to connect to the sqlserver1 using FQDN. nslookup shows correctly private address 10.0.0.4
I connected my pc to the vnet using the gateway. I'm able to ping MyVM using private adresss 10.0.0.5.
When I try to connect to the sqlserver1 using FQDN, I get error:
An instance-specific error occurred while establishing a connection to
SQL Server. The public network interface on this server is not
accessible. To connect to this server, use the Private Endpoint from
inside your virtual network. (Microsoft SQL Server, Error: 47073)
So it looks like that it's using the public dns record and not the private dns zone that I have created with the private endpoint. How can I connect to the database?
In this case, you can use NSLOOKUP FQDN on the PC to verify if the private DNS zone issue.
You need to correctly configure your DNS settings to resolve the allocated private IP address. You can follow On-premises workloads using a DNS forwarder and this blog about Azure SQL DB Private Link / Private Endpoint - Connectivity Troubleshooting.
It's not recommended to override a zone that is actively in use to
resolve public endpoints. Connections to resources won't be able to
resolve correctly without DNS forwarding to the public DNS. To avoid
issues, create a different domain name or follow the suggested name
for each service below.
To configure properly, you need the following resources:
On-premises network
Virtual network connected to on-premises
DNS forwarder deployed in Azure
Private DNS zones privatelink.database.windows.net with type A record
Private endpoint information (FQDN record name and private IP address)
I've created a SQL Server and then created a private link with my TESTVNET/SUBNET1 with private IP 10.1.1.4. I've now disabled Public access for the SQL server.
I have an Azure function running on App Service which I've VNET Integrated with VNET/SUBNET2.
Subnet 2 shows it's delegated to server farms. (also if someone can explain what does delegate to means, I found I cannot create any VM in that subnet as well, probably it's just can't be useful for any other purpose)
Now when my azure function tries to connect to DB. it fails with below error:
2020-08-30T15:25:45.216 [Error] Unhandled rejection SequelizeAccessDeniedError: Cannot open server "10.1.1.4" requested by the login. The login failed.
However, if I give the public FQDN it gives me below error.
2020-08-30T15:29:43.654 [Error] Unhandled rejection SequelizeAccessDeniedError: Reason: An instance-specific error occurred while establishing a connection to SQL Server. The public network interface on this server is not accessible. To connect to this server, use the Private Endpoint from inside your virtual network.
Here the Private DNS created by Private endpoint should have been ideally used to get the private IP of the SQL database, but it seems the function is not using the private DNS probably because not running in an isolated environment.
Now in my Azure function Application settings, I've added WEBSITE_VNET_ROUTE_ALL =1 which should mean that all the requests should be routed to VNET. So now If I enable public access internet, and allow Azure services to access DB (I think azure added the public IP by default). The function gets connected to the DB.
Now I want to understand where I'm going wrong and why is the private endpoint connection not working. Any help is appreciated.
In the DB firewall settings, I've allowed traffic from below to subnets:
Network Configuration
TESTVNET: 10.1.0.0/16
SUBNET 1: 10.1.1.0/24
SUBNET 2: 10.1.2.0/24
I've disabled Service endpoint for SQL in both SUBNET 1 and SUBNET 2. My NSG has default settings i.e.
AllowVnetInBound, AllowAzureLoadBalancerInBound, DenyAllInBound
AllowVnetOutBound, AllowInternetOutBound, DenyAllOutBound.
Since my private link has a private IP present in the same VNET I don't think NSG should have any impact.
New to Azure, testing things out. Thank you for your patience.
To make Azure Function connect to a private endpoint you will need to use VNET integration.
After your app integrates with your VNet, it uses the same DNS server that your VNet is configured with. By default, your app won't work with Azure DNS Private Zones. To work with Azure DNS Private Zones you need to add the following app settings:
WEBSITE_DNS_SERVER with value 168.63.129.16
WEBSITE_VNET_ROUTE_ALL with value 1
These settings will send all of your outbound calls from your app into your VNet in addition to enabling your app to use Azure DNS private zones. Reference here.
Then you could set up Private Link for Azure SQL Database. You can create an Azure VM from a new subnet in the same VNet to check connectivity using SQL Server Management Studio (SSMS). If you enable the private endpoint, you should get a client private IP from that Azure VM to connect the Azure SQL database with its FQDN.
For more information, you could read private endpoint VS service endpoint in this blog.
I followed the documentation guide here to configure an Azure DNS zone for a virtual network.
I then created a virtual machine on that virtual network and provisioned a virtual network gateway to allow my Azure web apps to communicate with the virtual machine using VNet integration. My web apps are then able to resolve against the virtual machines private IP as expected.
I then created an 'A' type record set within the DNS zone resolving a service name against the private IP of the virtual machine just like here.
However, when I then attempt to access the DNS configured service name that should resolve against the private IP address of the virtual machine, I get the following error:
curl: (6) Could not resolve host: xxxx.local
Am I missing something obvious here?
I can not reproduce this error following your steps:
Create an Azure VNet with a DNS private zone like private.test.com.
Create a VM and a VPN gateway on that VNet.
Enable VNet integration with my Azure web app service.
My web apps are able to resolve against the virtual machines private IP as expected. This could verify the Azure private DNS zone should work. Then I also create an A record for a custom name against the VM private IP address. Both scenarios work.
You could check if an A record is something like below picture in the private DNS zone.
Then you could verify if curl with http:// or without that, or without the specific port 9200, the error is still the same.
I suggest using SET WEBSITE_DNS_ command. This command will output the current DNS server that is being used by the web app. If the error Environment variable WEBSITE_DNS_ not defined is received, no custom DNS servers are configured for the web app. See more details about networking Related Commands for Azure App Services.