The AZ-700 course equips professionals with the skills to design, implement, and manage secure, reliable Azure networking solutions. It covers key topics like Virtual Networks, VPN and ExpressRoute connections, Azure Firewall, Load Balancers, Application Gateway, Private Link, and DNS. Designed for network engineers and architects, this course prepares candidates for the Microsoft Certified: Azure Network Engineer Associate certification by combining theoretical knowledge with hands-on Azure networking experience.
INTERMEDIATE LEVEL QUESTIONS
1. What are the key components of Azure Virtual Network (VNet)?
Azure Virtual Network (VNet) is a core component that enables secure communication between Azure resources, on-premises environments, and the internet. Key components include subnets, network security groups (NSGs), route tables, IP addresses, DNS settings, and peering. VNets help segment environments, enforce security policies, and control traffic flow within Azure.
2. What is VNet peering in Azure and how does it work?
VNet peering connects two virtual networks so they can communicate as if they were part of the same network. It supports low-latency, high-bandwidth communication across regions (global peering) or within the same region. Traffic remains within Microsoft’s backbone network, and peered VNets can share resources like DNS and private IPs if configured appropriately.
3. How does Azure Firewall differ from Network Security Groups (NSGs)?
Azure Firewall is a managed, stateful firewall that provides centralized control over traffic with built-in high availability and scalability. It supports application rules, network rules, and threat intelligence. NSGs, on the other hand, are stateless filters applied at the subnet or NIC level to allow or deny specific traffic. NSGs are simpler and more lightweight, but less feature-rich than Azure Firewall.
4. What is the role of Azure Application Gateway?
Azure Application Gateway is a layer 7 load balancer that manages web traffic for your applications. It supports features like URL-based routing, SSL termination, Web Application Firewall (WAF), and autoscaling. It is ideal for complex application delivery scenarios requiring deep packet inspection and secure traffic handling.
5. Explain the difference between Azure Load Balancer and Azure Application Gateway.
Azure Load Balancer operates at layer 4 (transport layer) and distributes inbound and outbound traffic based on TCP/UDP protocols. It is best suited for non-HTTP(S) workloads. Azure Application Gateway, in contrast, operates at layer 7 and supports features like cookie-based affinity and SSL offloading, making it ideal for web applications.
6. How does Azure Private Link enhance network security?
Azure Private Link allows you to access Azure services (like Azure Storage, SQL, or your custom services) over a private IP address within your VNet. This eliminates the need for data to traverse the public internet, significantly reducing exposure to security risks and data exfiltration.
7. What is Azure DNS and how does it support name resolution?
Azure DNS is a hosting service for domain name system (DNS) domains, providing ultra-fast name resolution using Microsoft’s global infrastructure. It allows you to manage DNS records using Azure APIs and integrates with Azure RBAC. You can also use Azure Private DNS Zones to manage DNS for VNets without needing a custom DNS server.
8. How do route tables and user-defined routes (UDRs) work in Azure?
Route tables in Azure define how traffic is routed in your VNet. User-defined routes (UDRs) allow customization of this behavior by overriding the default system routes. UDRs are especially useful in scenarios like forced tunneling, where traffic must go through an on-premises firewall or virtual appliance.
9. What is ExpressRoute and when should you use it?
Azure ExpressRoute is a private connection between your on-premises infrastructure and Azure datacenters, bypassing the public internet. It is ideal for scenarios requiring high security, reliability, and performance, such as enterprise-grade applications, financial transactions, or regulatory compliance needs.
10. What is the purpose of Azure Bastion?
Azure Bastion is a PaaS solution that provides secure and seamless RDP/SSH access to VMs in your VNet without exposing them to the public internet. It operates over SSL, protecting VMs from port scanning and brute force attacks while simplifying remote access management.
11. How can you monitor and troubleshoot network traffic in Azure?
Azure offers several tools for network monitoring and troubleshooting, including Network Watcher, which provides packet capture, connection monitoring, topology diagrams, and flow logs. Logs can be analyzed in Azure Log Analytics for identifying performance bottlenecks and diagnosing connectivity issues.
12. What is the difference between a Public IP and a Private IP in Azure?
Public IP addresses in Azure are routable from the internet and used to access services from outside the VNet. Private IP addresses are used within the VNet and are not accessible from the internet. Proper configuration of both ensures secure and efficient network communication.
13. How do NSGs enhance security in an Azure environment?
Network Security Groups (NSGs) act as distributed firewalls, allowing you to control inbound and outbound traffic at both the subnet and NIC levels. NSGs support rule-based filtering based on IP addresses, ports, and protocols, making them a crucial tool for segmenting and securing your Azure resources.
14. What are Service Endpoints and how do they differ from Private Link?
Service Endpoints allow you to secure Azure services to your VNet using Microsoft’s backbone. They provide secure access but use public IPs for the service. Private Link provides access over a private IP in your VNet, offering a more secure alternative that completely avoids the public internet.
15. What strategies can be used to secure hybrid connectivity in Azure?
Securing hybrid connectivity involves using VPN gateways or ExpressRoute with encryption, route filters, and Network Virtual Appliances (NVAs) for inspection. Azure Firewall, NSGs, and Azure Sentinel can further enhance monitoring and threat detection. Multi-layered defenses and adherence to the principle of least privilege are key in hybrid deployments.
ADVANCED LEVEL QUESTIONS
1. How does Azure Virtual WAN simplify enterprise-scale networking, and what are its architectural benefits?
Azure Virtual WAN is a networking service that enables simplified, large-scale connectivity across branch offices, on-premises datacenters, and Azure regions. It creates a hub-and-spoke architecture where the Virtual WAN hub acts as the central connection point for all networking components. One of its main benefits is centralized policy and route management. It supports SD-WAN, VPN, and ExpressRoute connections natively and offers built-in high availability and scalability. The integration with Azure Firewall and other NVAs at the hub level enables centralized security policies, making it ideal for enterprises seeking to manage hybrid and branch connectivity at scale with operational efficiency and reduced overhead.
2. Compare and contrast Azure Application Gateway and Azure Front Door in terms of performance, security, and routing capabilities.
Azure Application Gateway and Azure Front Door both operate at Layer 7 but serve different scenarios. Application Gateway is region-specific and designed for internal or regional load balancing with support for Web Application Firewall (WAF), SSL termination, and URL-based routing. It integrates deeply with virtual networks and supports internal site hosting. Azure Front Door is a global service offering low-latency, high-performance content delivery with intelligent routing at the DNS level. It supports SSL offloading, WAF, session affinity, and global failover. In hybrid deployments, using both together offers edge-level routing via Front Door and internal traffic management via Application Gateway, ensuring optimal global performance and regional security.
3. How do Azure Network Security Groups (NSGs) interact with User Defined Routes (UDRs), and what is the precedence in traffic control?
Azure NSGs and UDRs are both critical for traffic control, but they serve different purposes. NSGs act as firewalls, filtering inbound and outbound traffic based on 5-tuple rules—source/destination IP, port, and protocol. UDRs, on the other hand, dictate how packets are routed between subnets and virtual appliances. While UDRs decide where the traffic goes, NSGs determine whether it is allowed or denied. When a packet is transmitted, the routing decision via UDRs is applied first, and then NSG rules are enforced at the source (outbound) and destination (inbound) endpoints. Misconfigurations between NSGs and UDRs can result in unreachable services despite correct routing.
4. What are the advantages of using Azure Private Link over Service Endpoints, and when should each be used?
Azure Private Link offers more secure and private access to Azure services by mapping them to private IP addresses within your VNet. Unlike Service Endpoints, which expose services over public IPs while restricting access to specific VNets, Private Link ensures that traffic never leaves the Microsoft backbone network and is completely isolated from the public internet. This is ideal for scenarios involving regulatory compliance, data residency, and sensitive data handling. Service Endpoints are simpler to implement and suitable when you need broader access control but don’t require full network isolation. For maximum security, particularly with services like Azure SQL, Private Link is preferred.
5. How do Azure Route Server and BGP facilitate dynamic routing with NVAs, and what are the implementation best practices?
Azure Route Server automates the exchange of Border Gateway Protocol (BGP) routes between your Azure virtual network and your Network Virtual Appliances (NVAs). This eliminates the need for manual route configuration and supports dynamic route updates, which is especially valuable in large or changing environments. Best practices include ensuring the NVA supports BGP, deploying the Route Server in a dedicated subnet, and securing BGP sessions with authentication. Additionally, care should be taken to avoid route conflicts and ensure proper AS path prepending or route filtering to maintain control over route advertisements.
6. Describe the steps and considerations involved in designing a hybrid network using Azure VPN Gateway and ExpressRoute.
Designing a hybrid network involves selecting the right connectivity method: VPN Gateway for encrypted tunnels over the public internet or ExpressRoute for private, dedicated connectivity. Often, both are implemented in an active-active or failover scenario. Key considerations include capacity planning, latency, bandwidth requirements, routing preferences (BGP vs static), and security. ExpressRoute offers more predictable performance, while VPN is cost-effective and easier to implement. When combining both, forced tunneling must be configured correctly to avoid asymmetric routing. Redundancy, high availability, and monitoring using Network Watcher and Azure Monitor must be incorporated for enterprise-grade reliability.
7. How can you design a secure and scalable Azure network architecture for multi-region deployment?
For multi-region deployments, a hub-and-spoke model with regional hubs interconnected via VNet peering or Azure Virtual WAN is recommended. Each region hosts its own application resources in spoke VNets, while central services like firewalls, DNS, and logging are placed in the hub. Global resources can be load-balanced using Azure Front Door, while Application Gateway handles regional traffic. Route tables and NSGs ensure segmentation, and private endpoints secure service access. Identity, logging, and alerting should be consistent across regions, leveraging Azure Policy and Defender for Cloud. Scalability is achieved through autoscaling VNets and modular subnetting.
8. What are the network security implications of exposing services through public IPs in Azure, and how can they be mitigated?
Exposing services via public IPs increases the attack surface, making them vulnerable to threats like DDoS, brute-force attacks, and unauthorized access. Mitigation strategies include using Azure DDoS Protection Standard, applying NSGs and Azure Firewall to restrict traffic, and monitoring access logs with Network Watcher. Whenever possible, use Private Link or Service Endpoints to avoid public exposure altogether. For administrative access, Azure Bastion or just-in-time VM access (via Microsoft Defender for Cloud) can help secure remote connectivity without public RDP/SSH ports.
9. How does Azure Firewall Policy help in managing security across multiple firewalls, and what is the role of hierarchy in it?
Azure Firewall Policy enables centralized management of multiple Azure Firewall instances by defining and applying rule collections from a single policy. Policies support rule types (DNAT, network, application), threat intelligence, TLS inspection, and logging. Policies can be assigned at the firewall level or inherited from a parent policy, allowing reuse across environments (e.g., dev, test, prod) with consistent rules. The hierarchy enables base-level policies (e.g., global restrictions) to be defined once and layered with local overrides, enhancing manageability and scalability in enterprise scenarios.
10. How can Azure Monitor and Network Watcher be integrated to diagnose network latency and packet loss issues?
Azure Monitor collects metrics and logs across services, while Network Watcher provides tools like Connection Monitor, Packet Capture, and Network Performance Monitor. Together, they allow end-to-end visibility. For instance, Connection Monitor tests TCP connectivity between resources, providing insights into latency and failure rates. Packet Capture helps isolate the root cause of traffic anomalies, while NSG flow logs analyzed through Log Analytics show traffic paths and drop reasons. Integrating these tools into a dashboard allows proactive monitoring and rapid troubleshooting of performance bottlenecks or misconfigurations.
11. What is the difference between UDR-based routing and BGP-based routing in Azure, and when is each approach appropriate?
User Defined Routes (UDRs) are static routes configured manually, allowing precise control of traffic paths. BGP-based routing is dynamic and exchanges routes between peers based on network topology. UDRs are simple and suitable for smaller, static environments or specific traffic redirection like service chaining. BGP is preferred in complex, hybrid, or large-scale environments where routes change frequently, as it automates route distribution and supports path optimization. In hybrid setups using ExpressRoute or VPN, BGP is essential for ensuring seamless failover and route management.
12. How can you enforce Zero Trust principles in Azure networking design?
Zero Trust in Azure networking involves assuming breach and verifying explicitly at every layer. Network segmentation using subnets, NSGs, and Application Security Groups (ASGs) enforces least privilege. All exposed services should use Private Link, and identity should be verified using Azure AD. Logging, monitoring, and access reviews are vital. Azure Firewall and Web Application Firewall (WAF) should inspect traffic, while Azure Policy ensures compliance. Continuous assessment using Defender for Cloud enables adaptive threat protection. The goal is to reduce the blast radius and validate every connection explicitly before allowing access.
13. What is forced tunneling and what are the key configuration steps in Azure?
Forced tunneling directs outbound traffic from Azure resources back to an on-premises network for inspection before reaching the internet. This is essential for regulatory compliance and centralized control. Configuration involves setting up a default route (0.0.0.0/0) using UDRs pointing to the VPN Gateway, and enabling BGP if needed. Azure’s default system routes must be overridden carefully to avoid losing Azure platform connectivity. Exceptions are handled using service tags or route filters. Azure Firewall or NVA on-premises typically inspects or filters the traffic.
14. How can you design high availability for critical network paths in Azure?
High availability is achieved by deploying redundant components in different availability zones, using active-active VPN Gateways, zone-redundant Application Gateways, and replicating services across regions. Load balancers distribute traffic across healthy instances, while Route-based routing with health probes ensures traffic is rerouted automatically in case of failure. Using Azure Traffic Manager for global failover and integrating with Azure Front Door for DNS-level routing also enhances resilience. Monitoring tools must be configured to detect issues and trigger failover or alerts.
15. Explain how Azure DNS and Private DNS Zones are used to support hybrid and secure name resolution.
Azure DNS enables hosting of public DNS zones, while Azure Private DNS Zones allow DNS resolution within VNets without needing custom DNS servers. In hybrid environments, Private DNS Zones can be linked across VNets or with on-premises networks using DNS forwarders. This ensures internal services are discoverable securely without exposing them externally. Split-horizon DNS setups using conditional forwarding enable organizations to resolve both internal and external names appropriately. Azure DNS also integrates with RBAC for controlled access and audit logging.