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Virtual networks (VNets) in Azure provide the foundation for secure network connectivity. They allow Azure resources like virtual machines (VMs) and applications to securely communicate with each other, the internet, and on-premises networks. To secure these networks, Azure provides several tools and features:
NSGs are used to filter network traffic to and from Azure resources in an Azure VNet. An NSG contains security rules that allow or deny inbound or outbound network traffic based on several parameters such as protocol, source and destination IP address, port, and direction (inbound or outbound).
ASGs help manage security rules based on applications or groups of virtual machines. This allows for a more granular control by grouping VMs with similar functions and applying security policies at the application level.
A managed, cloud-based network security service that protects Azure VNets resources. Azure Firewall provides a fully stateful firewall as a service with built-in high availability and unrestricted cloud scalability.
VNet peering connects two VNets within the same or different Azure region. Traffic between peered VNets is private and secure. Network routing is done through the Microsoft backbone infrastructure, not through a public internet exchange.
These services enable secure connectivity between Azure VNets and on-premises networks. A VPN gateway is used for encrypted traffic over a public connection, while ExpressRoute provides a private connection that does not go over the public internet.
This service provides enhanced DDoS mitigation features to defend against Distributed Denial of Service (DDoS) attacks.
Consider a multi-tier application setup with a web tier, application tier, and data tier. Each tier is segregated into its own subnet within a VNet.
NSG Rule | Direction | Protocol | Source | Destination | Port | Action |
---|---|---|---|---|---|---|
Web-HTTP | Inbound | TCP | Any | Web Tier | 80 | Allow |
Web-HTTPS | Inbound | TCP | Any | Web Tier | 443 | Allow |
Deny-All | Inbound | Any | Any | Any | Any | Deny |
NSG Rule | Direction | Protocol | Source | Destination | Port | Action |
---|---|---|---|---|---|---|
App-WebAccess | Inbound | TCP | Web Tier | App Tier | Any | Allow |
Deny-All | Inbound | Any | Any | Any | Any | Deny |
NSG Rule | Direction | Protocol | Source | Destination | Port | Action |
---|---|---|---|---|---|---|
Data-AppAccess | Inbound | TCP | App Tier | Data Tier | Any | Allow |
Deny-All | Inbound | Any | Any | Any | Any | Deny |
For the web tier, only HTTP and HTTPS traffic is allowed into the subnet, while the other tiers have restrictions that only allow traffic from specific subnets or tiers.
Securing the connectivity of virtual networks in Azure is a critical task that requires a comprehensive understanding of network security features and best practices. The aforementioned tools and features, along with adherence to security fundamentals, create a robust defense against potential threats to network connectivity. By leveraging these capabilities, organizations can ensure the secure and efficient operation of their services on the Azure cloud, which is an essential skill set validated by the AZ-500 Azure Security Technologies certification.
Azure service endpoints extend your virtual network private address space, and the identity of your VNet, to Azure services, providing a direct connection.
Answer: A, C
Both Network Security Groups (NSGs) and Azure Firewall can be used to filter network traffic between subnets within an Azure Virtual Network.
You can only assign one NSG to a given network interface in Azure.
Answer: A
Azure VPN Gateway is used to connect on-premises networks to Azure virtual networks through site-to-site VPNs.
Azure Bastion provides secure and seamless RDP/SSH connectivity to your virtual machines directly from the Azure portal over SSL without the need for a public IP on the VM.
Answer: C
Azure DDoS Protection Standard is designed to protect Azure resources from the impact of Distributed Denial of Service (DDoS) attacks.
Answer: C
Azure Network Watcher provides tools for monitoring, diagnosing, and gaining insights into network performance and issues, not for load balancing.
User-Defined Routes (UDRs) are custom route tables that give you the control to define how packets should be routed within a VNet, and can be used to override Azure’s default system routes.
Azure ExpressRoute allows you to extend your on-premises networks into the Microsoft cloud over a private connection facilitated by a connectivity provider.
Answer: B
Azure Front Door Service provides a scalable and secure entry point for fast delivery of your global web applications leveraging the Microsoft global edge network.
Azure Application Gateway offers a Web Application Firewall (WAF) that provides centralized protection of your web applications from common exploits and vulnerabilities.
Answer: C
Azure Private Link enables you to access Azure services (such as Azure SQL Database, Azure Storage, and Azure Cosmos DB) and your own services privately and securely within your VNet and on-premises network.
Azure Virtual Network Security is the protection of the Azure virtual network environment, including subnets, from external attacks.
A network security group (NSG) is a security group that controls traffic flow in and out of a virtual network subnet.
You can create a network security group (NSG) in Azure using the Azure portal, Azure PowerShell, Azure CLI, or Azure Resource Manager templates.
Traffic filtering is the process of controlling network traffic using network security groups (NSGs) to block or allow traffic based on source, destination, and port.
You can filter network traffic in Azure by creating network security groups (NSGs) and configuring rules to allow or block traffic.
Virtual network peering is the process of connecting two virtual networks in Azure to allow communication between them.
You can enable virtual network peering in Azure by creating a peering connection between two virtual networks in the same region.
Azure Bastion is a service that provides secure and seamless RDP/SSH connectivity to virtual machines directly from the Azure portal.
You can set up Azure Bastion by creating an Azure Bastion resource and assigning it to the virtual network where your virtual machines are located.
Application security groups (ASGs) are used to simplify network security management by allowing you to group virtual machines and apply network security policies to them as a group.
You can create an application security group (ASG) in Azure using the Azure portal, Azure PowerShell, Azure CLI, or Azure Resource Manager templates.
Some best practices for securing virtual networks in Azure include using network security groups (NSGs) to control traffic, implementing virtual network peering for communication between virtual networks, using Azure Bastion for remote connectivity, and regularly reviewing and updating network security policies.
You can manage network security in Azure using the Azure portal, Azure PowerShell, Azure CLI, or Azure Resource Manager templates to create and configure network security groups (NSGs), peering connections, and application security groups (ASGs).
You can monitor network traffic in Azure using Azure Monitor and Azure Network Watcher to gain visibility into network traffic and troubleshoot network issues.
Common network security threats in Azure include DDoS attacks, network scanning and port scanning, phishing attacks, and malware attacks.
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