Until now I assumed that the traffic flowing between 2 azure resources (say between an Azure VM & Storage Account or a Key Vault) was through the internet, if private and service endpoints are not configured. But today a colleague of mine shared an article where it says that all the traffic between the Azure datacenters does not go through the internet, it's on Microsoft's backbone network only. Link to the article - https://azure.microsoft.com/en-in/blog/how-microsoft-builds-its-fast-and-reliable-global-network/
Now there could be 2 things:
Either the article is now outdated (it is from 2017) and no longer true, and w/o any special configuration the traffic between 2 azure resources flows through the internet, or,
The traffic indeed flows through the Microsoft's network and not through the internet, but in that case, what's the benefit of Private endpoint apart from the fact that we can assign a private IP to a PaaS service.
Any insights in this regards would be highly appriciated. Thanks in Advance!
Yes all the traffic which is between Azure services travels over Microsoft backbone network.
This is documented here
Yes, any traffic between data centers, within Microsoft Azure or between Microsoft services such as Virtual Machines, Microsoft 365, XBox, SQL DBs, Storage, and virtual networks are routed within our global network and never over the public Internet, to ensure optimal performance and integrity.
Service endpoints provide an extra layer of isolation and security , as per Microsoft Docs :
Network connections can only be initiated by clients connecting to the private endpoint. Service providers don't have routing configuration to create connections into service consumers. Connections can only be established in a single direction.
To understand the private endpoints in better way I would recommend to read more about Private Link Service as well.
The difference is that services with Private Endpoint are not reachable from anywhere else but your VNet.
If you have an VM -> Storage without private endpoint, the traffic will go over the MS network, but your storage endpoint is public (I can reach it from my laptop :) )
If you place your storage in a VNet with private endpoints, then I need to be able to access the VNet in order I can reach the storage endpoint
Related
When we have a requirement to connect to 2 different storage accounts (SAME service ie Azure Storage / 2 instances) from a VNET/Subnet,
Using-
1.Private Endpoints implies that we need one Private Endpoint for each storage account.
(And single private endpoint can be used across subnets in the vnet)
2.Service Endpoints implies that a SINGLE Service Endpoint is created for STORAGE SERVICE as a whole and it gets re used for different storage accounts.
(And each subnet needing access to storage accounts would need its own service endpoint)
Would this inference be correct?
Regards,
Aditya Garg
What you mentioned is the correct, however, there are more differences and use-case for both these services. One of the major difference I would say is
Private Endpoints grant network access to specific resources behind a given service providing granular segmentation. Traffic can reach the service resource from on-premises without using public endpoints.
A Service Endpoint remains a publicly routable IP address. A Private Endpoint is a private IP in the address space of the virtual network where the private endpoint is configured.
One should also need to know their limitations
Service endpoint limitation
Private endpoint limitation
Some other reference
If I am setting up an Azure SQL Database in a vnet which Azure App Service and Azure Function will access. Is using both Subnet Delegation and Service Endpoints the right way to go? I didn't fully understand the documentation.
Regarding subnet delegation, I read this Microsoft article and this stackoverflow post, which stated:
When you delegate a subnet to an Azure service, you allow that service to establish some basic network configuration rules for that subnet, which help the Azure service operate their instances in a stable manner.
That sounds like a good thing but makes me wonder how it worked efficiently w/o subnet delegation.
As for Service Endpoints, I read this Microsoft article, which states:
Virtual Network (VNet) service endpoint provides secure and direct connectivity to Azure services over an optimized route over the Azure backbone network. Endpoints allow you to secure your critical Azure service resources to only your virtual networks. Service Endpoints enables private IP addresses in the VNet to reach the endpoint of an Azure service without needing a public IP address on the VNet.
Does that mean I cannot reach the Azure SQL Database from my home machine w/a firewall rule?
They both sound like they have the same benefits and I'm struggling to understand the difference. I suppose the larger question is should I enable both for the simple architecture outlined above.
In the Microsoft service endpoints documentation they also mention:
Microsoft recommends use of Azure Private Link for secure and private access to services hosted on Azure platform. For more information, see Azure Private Link.
For some reason that seems like an Azure to on-premise thing.
• You cannot use a ‘Subnet Delegation’ along with a ‘Private endpoint’ since that subnet is delegated for the said service, in your case, the Azure SQL Database. Through a subnet delegation, you can define the NSG association for it, as well as associate multiple delegated subnets to a common NSG. You can also define the IP Address space for the delegated subnet, the route table association with it, the custom DNS entry configuration in Azure DNS as well as define the minimum number of IP Addresses available for that delegated subnet. Similarly, with regards to service endpoint, these stated functions are not available.
• In service endpoint, you do not have control over the routing mechanism as well as the IP address related allotment, reservation, or configuration. Also, managing DNS entries for the resources managed through them and controlling them through a firewall or NAT gateway isn’t required unlike a subnet delegation because all these things are managed by Microsoft Azure’s backbone network on your behalf.
Thus, both have their own features and specifications for enabling you to configure according to your own requirements.
Does that mean I cannot reach the Azure SQL Database from my home machine w/a firewall rule?
Yes, you will have to create a firewall rule to allow the access from on-premises system to Azure SQL Server/Database and configure the service endpoint accordingly to allow the VPN client IP Addresses for accessing the same over public internet.
Also, through Azure private link, you won’t be able to connect from on-premises to Azure as it uses a private IP address and a private DNS zone entry related to it to connect to Azure resources in the same virtual network.
To know more regarding the configuration of Azure service access from on-premises network, kindly refer to the below given link: -
https://learn.microsoft.com/en-us/azure/virtual-network/virtual-network-service-endpoints-overview#secure-azure-service-access-from-on-premises
Also, refer to the below snapshots regarding the configuration and selection of service endpoint for a particular subnet: -
can anyone explain difference between Azure Application Gateway, Virtual Network Gateway, Virtual WAN, ExpressRoute, Arc and Private Link, please?
It seems to me all services are pretty similar helping with connecting either on-prem to Azure, in-Azure to in-Azure or public to Azure.
They're similar in that they all involve network traffic, but that's pretty much where the similarities end.
Application Gateway is a Layer 7 load balancing service with advanced features like SSL termination. It's used to route client requests to your applications.
Virtual Network Gateway is a VPN gateway for point-to-site (user) and site-to-site (office/datacenter) VPN connections to your own Azure VNETs. This would, for example, allow you to RDP into Azure VMs from your on-prem office using their private IPs.
ExpressRoute is similar to site-to-site, however it doesn't use IpSec tunnels, it's a dedicated, unencrypted connection from your location directly into Microsoft's backbone. (i.e. you don't traverse the public internet). There's no encryption and the connection is faster. This is a service you need to work with a 3rd party internet provider to implement.
Virtual WAN is more like a networking hub where there would be many site-to-site, point-to-site, ExpressRoute, etc... connections spanning a wide area (as the name implies). This would be for large enterpise organizations with many on-prem locations.
Arc is a means of adding your on-prem resources into Azure for management. e.g. you have a physical server somewhere and you want to manage it though ARM/portal.
Azure Private Link is a feature of many Azure services (storage, SQL PaaS, etc..) which allows you to create a private DNS record and assign a private IP address on your internal VNETs. This is used when you want to disable all public network access to a resource and only allow access from within your own VNET.
I have barely scratched the surface of the differences here, but suffice it to say, there are many differences. From this page, you can type the service name into the search and get more specific details on the offering. Hope this helps.
https://learn.microsoft.com/en-us/search/?terms=networking%20in%20azure
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.
I build an architecture, where you can trigger an Azure Function to push data into a Cosmos DB, which lies behind my DMZ. Some implementation guidelines state, that a service endpoint should be always enabled if possible. However, if I do so, the Cosmos DB is potentially exposed to the Internet (although I would not allow any IPs in the Cosmos DB firewall). With exposure I mean the order of handling services in Azure (https://msdnshared.blob.core.windows.net/media/2016/05/1.bmp). Thus, the Cosmos DB would have by default a public endpoint.
Can I restrict any public access from the internet, except blocking all IP addresses?
Can I restrict any public access from the internet, except blocking
all IP addresses?
Actually, By enabling service endpoint, you have limited that only requests originating from that subnet could access the Azure Cosmos DB. Traffic from your VNet to the Azure service always remains on the Microsoft Azure backbone network. So, it's a secure way to access resources in Azure.
After enabling a service endpoint, the source IP addresses of virtual machines in the subnet switch from using public IPv4 addresses to using their private IPv4 address, when communicating with the service from that subnet. Also, the default NSG associated with that subnet continues to work with service endpoints, read here. If you want to deny all outbound internet traffic and only allow access to cosmos DB from that subnet, you could add service tag as the destination in the outbound rules in NSG.
edit
You could have a look at this Azure private link(preview), but it seems it's not available for Azure Cosmos DB Account yet.
Azure Private Link enables you to access Azure PaaS Services (for
example, Azure Storage and SQL Database) and Azure hosted
customer/partner services over a Private Endpoint in your virtual
network. Traffic between your virtual network and the service
traverses over the Microsoft backbone network, eliminating exposure
from the public Internet.