When an Azure PaaS service (ex:App Service) makes a call to another PaaS service in the same region, say SQL Database, is that traffic routed through Public Internet or routed entirely through Azure backbone network (like: for DNS resolution and other subsequent network hops). Is there any difference in the way this traffic is routed if the services are in different regions?
I got the answer, so I thought it will help the community if someone has the same question.
The PaaS - PaaS traffic stays entirely within Azure backbone network.
Link here
Related
I deploy my web application to an App Service instance on Premium tier. My web application makes outbound requests to external resources on the Internet.
In order to secure the connection with one of these external resources so I can reach it with a private IP address, my plan is to create a Site-to-Site VPN from Azure to Oracle Cloud Infrastructure (where the external resource resides). Then, I plan to use the VNET Integration for outbound traffic and connect my App Service to my VPN.
My question is - will the web application still be able to reach the other external resources on the Internet with their public IPs? I believe the answer is related to routing tables but I can't wrap my mind around it.
Just because you integrate a Regional VNet (I'm assuming) doesn't mean the app service won't be able to make outbound connections. Pretty much like
When you integrate your app service with your VNet that has the site-to-site VPN, traffic from your app service will traverse the Azure network rather than going out to internet, assuming your app service is using an RFC1918 address for your infrastructure. If you want to secure the traffic even further, then your app service would need to be hosted inside an App Service Environment
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
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
Does an Azure Vnet improve or degrade performance compared to a connection via public endpoint?
By performance I mean latency or throughput.
For example when connecting from a web app to a database.
If communicating resources are on the same VNet OR in VNets that are on the SAME Azure Region, there will be NO degradation.
On the oder hand, if the peer VNets are on different Azure Regions, there will be degradation because the peers are in different data centers.
Vnets are primarily used to add an additional layer of security. They do not offer performance benefits - but if you use Vnet connectivity in any part of your application then you need to be aware of the correct configuration to avoid (unnecessary) degradation.
Lets' say for example you have a simple web app made up of an App Service instance with a SQL Database. If you connect your App to a Vnet to access some on-premise resource (via VPN or Expressroute), and that vnet is configured with forced tunnelling to on-premise then you will have degradation: Traffic from the web app to SQL db is getting hair-pinned via your on-premise network. If you then set-up a Service Endpoint for the SQL database on your VNet, the traffic will stay in Azure and you will get optimal routing Source. However it won't be any faster than if you had no VNet.
For a more detailed explanation take a look at this blog: Improve security and performance with Virtual Network Service Endpoints and Firewalls for Azure Storage
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.