Unable to connect to Azure SQL through Virtual Network Gateway - azure

I have SQL Azure Database Server (not managed instance). When setup last year, I added Azure Virtual Network Gateway, and I could access the database via the VPN connection, without whitelisting the IP.
We didn't use this connection via gateway since Jan 2020. There was only couple of developers connection but had their IP whitelisted.
Recently, we tried accessing the database using this connection, and it doesn't work. Prompting to whitelist the IP. Has something changed?

It seems that you just enable Azure virtual network service endpoints for your Azure SQL database server (not managed instance) and add this subnet to your SQL network rules. With service endpoint, the traffics go over the Internet but restrict over the network. Service endpoints and Private endpoints are two different things.
To connect to your Azure SQL database via a VPN connection, you could use a private link. Private Link allows you to connect to various PaaS services in Azure via a private endpoint. You could get the detailed steps from https://learn.microsoft.com/en-us/azure/azure-sql/database/private-endpoint-overview
Alternatively, you could try to use a TCP proxy server to forward traffic to the public IP address for SQL Database. Reference: https://argonsys.com/microsoft-cloud/library/using-a-tcp-proxy-to-connect-to-sql-database-over-vpn/

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SSMS IP address changes after disconnecting from Azure SQL server

We are connecting to Azure SQL server for our work through SSMS. We are whitelisting all the developers IP in Networking section of Azure SQL Server. Whenever we close SSMS connection all the time SSMS IP get changes. Then we need to go and update the new IP in Azure portal. Why SSMS changes the IP all the time. Any solution for this in SSMS settings.
Your ISP is properly providing you a dynamic IP. You can check your egress IP with a lot of online IP discover services. If it changes overnight/day e.g. https://wtfismyip.com/
To avoid dealing with IP Whitelists you could use a VPN Gateway or Express Route to tunnle your Devs to an Azure VNET and connect the Azure SQL DB with private Link into that VNET.
Alternatively, you could use a Bastion host to run SSMS there.
But in the End, there is nothing which you or Microsoft can do on Azure Side to prevent your client IP from changing when your ISP doesn't provide you a static IP.
Of course, you can ask them to upgrade your internet to a static IP address, or do you use multiple egress IPs in your company? In this case maybe speak with your network admin to get all egress IPs and whitelist those.

Access Azure Private Endpoint Using Azure VPN

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

Why we have a lot of connections between app services from same resource group?

We have three App Services in Azure (API1, API2, API3).
API2 is getting data from CosmosDB.
API3 is getting data from other CosmosDB.
Main API1 calls API2 to get some data. Then using this data calls API3.
We have poor performance of API1 and we are trying to figure out why. We noticed that there are too many connections in metrics. Also we have issue with SNAT ports.
We tried to setup these APIs to the same VNet but it doesn't help and we are not sure how to set up it correctly.
Do you have any idea what we should setup?
UPDATE:
Seems like VNet helped us with SNAT ports issue but performance of API was still very poor.
What really helped us was change from Windows to Linux. When all APIs runs on the Linux servers we don't see any connections anymore.
Not sure what's specific configurations about three APIs on your side. If you want to use IP from Vnet instead of an external one, you can use a separate environment ASE.
Alternatively, you can use a private link to the app service. By using Private Endpoint, you can connect privately to your web app. Read Connect privately to a web app by using Azure Private Endpoint (Preview).
Today, you can secure this connection using VNet service endpoints
which keep the traffic within the Microsoft backbone network and allow
the PaaS resource to be locked down to just your VNet. However, the
PaaS endpoint is still served over a public IP address and therefore
not reachable from on-premises through Azure ExpressRoute private
peering or VPN gateway. With today’s announcement of Azure Private
Link, you can simply create a private endpoint in your VNet and map it
to your PaaS resource (Your Azure Storage account blob or SQL Database
server). These resources are then accessible over a private IP address
in your VNet, enabling connectivity from on-premises through Azure
ExpressRoute private peering and/or VPN gateway and keep the network
configuration simple by not opening it up to public IP addresses.
For more information, you could read here.

Connect to Azure SQL Server from computer with dynamic external IP

I am trying to connect an on-premises laptop with dynamic external IP to our Azure SQL Server. To do this, I created a virtual network gateway and connected the laptop to the gateway. Also, I added a private endpoint to the SQL server. After this, I can successfully connect to the SQL server IP using telnet, and if I resolve the SQL server FQDS in hosts file, I can connect to the server via SSMS. But without hosts file, the laptop always tries to connect to the SQL server via its public endpoint/address.
I found the following article: https://techcommunity.microsoft.com/t5/azure-database-support-blog/azure-sql-db-private-link-private-endpoint-connectivity/ba-p/1235573 The article is great. It recommends using your own DNS server to resolve the SQL server FQDN to the local IP. Unfortunately, the laptop does not have access to any custom DNS, so this solution does not suit.
There are two questions:
Is there any possibility to establish connection between an on-premises computer with dynamic IP and an Azure SQL server using a private endpoint but without own DNS server?
If the answer to the first question is "No", is there another way to connect an on-premises computer with dynamic IP to an Azure SQL server using any other Azure application(s)?
First of all, you can not use FQDN without DNS service. So you indeed need a custom DNS server in using FQDN of the server in connection strings for your clients to connect from on-premise VM to the Azure SQL server.
Since you are using a laptop, the DNS servers used by your computer are most likely specified by your ISP. You have no more control over it or ask your ISP to configure the DNS forwarder. Otherwise, you need to deploy a DNS server in your internal network. Currently, in this scenario, the best method is to use the HOSTS file on the local machine to override the Public DNS.
However, if you don't like using the HOSTS file, you can provision an Azure VM as the DNS server in the same Azure virtual network as the virtual network gateway.
Main steps:
Deploy an Azure VM, and RDP to that VM and run the PowerShell commands to install the DNS server role.
Install-WindowsFeature -Name DNS -IncludeManagementTools
Get-WindowsFeature *DNS*
Add Azure DNS (168.63.129.16) as a forwarder on your custom DNS server according to the step 5 in this blog. If you do not want to use forwarder you can also create a forward lookup zone and added manually the host to match the FQDN. You could read On-premises workloads using a DNS forwarder for more details.
After you have configured the DNS server and set the DNS forwarder. You could change the DNS server of Azure VNet to your Azure VM's private IP address.
Restart your Azure VM and re-download the VPN client package and re-connect the VPN connection to make the networking update. Check the DNS server on the local VPN client machine and set the DNS server to the custom DNS server in the TCP/IP settings. Then you will look up your private IP address via the default FQDN of Azure service.
In my example, I am using Azure storage account but it works the same with Azure
SQL database when using a private endpoint on the Azure and P2S VPN connection.
In this way, it requires that there are not any other VPN connections except the
P2S VPN connection on the local machine.
Then you could resolve the Azure SQL server FQDN to the private IP address of the private endpoint. However, it perhaps does not have a better performance to connect to Azure SQL Server with a VPN connection than directly connect to it through the public Internet and public DNS sevice.

Connect to Azure Database for Postgresql through VPN

While configuring an Azure managed Postgres service, I am trying to configure connecting from local machines through VPN.
I can connect to the DB when white-listing IPs in Connection Security.
I have added the subnet the VPN-gateway is connected to to the VNET Rules – this doesn't seem to make a difference.
I can connect to VMs through the VPN from my local machine.
However to make that work, I added the VMs' (private IP, Azure URL)-pairs to my local machines hosts-file.
I can't find any IP for the DB-service (which seems to make sense for a managed service), so I can't make the same trick.
The error I'm getting, when trying to connect to the DB, is similar to the ones I got before adding hosts mappings.
This all leads me to believe I need some way of having Azure resolve the URL (which might also preempt the need for hosts-mappings in general).
From this article, I tried setting my DNS for 168.63.129.16, but that doesn't work at all (nothing at all is resolved).
Is there a way (and if so, how) to connect from a local machine to an Azure Database for Postgresql service through a VPN gateway?
I don't think there is a way to do this as your desired. You want to map an Azure database logical server private IP to your local hosts file, then access it via VPN gateway.
You only know the public IP for the Azure database server. The public IP addresses of Azure services change periodically. You could find an IP address list by filtering your region. It does not recommend to use such a dynamic IP address. Refer to this blog.
Since Azure database is a fully managed Platform as a Service (PaaS) Database Engine not IaaS like Azure virtual machines, It's public and does not expose the database server private IP address. We only could access the database via Azure database server name over the Internet.
Furthermore, if you want to restrict its access only from a private network with virtual Network service endpoints. However, this works to allow resources like Azure VM in the authorized subnet to access directly your Azure database in a private network, could not guarantee that if you could access the Azure database from your local machine via VPN. This seems no on-premise route to your Azure database.

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