Table of Contents
The first step in troubleshooting is to ensure that the virtual network and its related components are configured correctly. Verify the following elements:
Azure Network Watcher provides tools to monitor, diagnose, and gain insights into network performance and health. Utilize the following features:
Azure Resource Health provides personalized information about the health of your Azure resources. Check this for any known issues with the Azure platform that may be affecting your virtual network connectivity.
The Service Health dashboard provides a view of the health of Azure services across regions. If there is a known issue with Azure services that could impact networking, it will be listed here.
Issue Description | Possible Cause | Resolution |
---|---|---|
VMs cannot communicate over the VNet | Misconfigured NSG rules or route tables | Adjust NSG settings, Check Route Tables |
Cross-VNet connection not working | Overlapping address spaces, Missing peering | Ensure unique address spaces, Configure VNet Peering |
Unable to connect to VM with RDP/SSH | NSG blocking RDP/SSH port | Update NSG to allow RDP (Port 3389) or SSH (Port 22) |
Connectivity issues to DNS servers | Incorrect DNS server or settings | Verify DNS settings and VM’s DNS configuration |
Slow network performance | Insufficient bandwidth or size of VM | Scale network resources or VM size |
For advanced issues, you may need to delve deeper:
In conclusion, isolating and resolving virtual network connectivity issues in Azure involves a strategic approach to configuration validation, tool utilization, and understanding both common and complex issues. As an Azure Administrator preparing for the AZ-104 exam, mastering these troubleshooting techniques will not only help in passing the exam but also effectively manage Azure environments in real-world scenarios.
NSG rules can affect virtual network connectivity within the same subnet by allowing or denying traffic to and from resources within that subnet.
C) NSG (Network Security Group) rules
When facing connectivity issues between resources on the same virtual network, the first thing to check is Network Security Group rules, as they define the allowed and denied traffic within the network.
Azure automatically creates system routes that enable communication within a virtual network, between virtual networks, on-premises networks, and the Internet.
B) To override Azure’s default system routes
User Defined Routes are used to override Azure’s default system routes to customize network traffic flow within and between subnets.
The Azure Network Watcher’s IP flow verify tool can be used to diagnose if network security groups (NSGs) or other network traffic filters are blocking communication to or from a virtual machine.
C) Azure Network Watcher’s Connection Troubleshoot
Azure Network Watcher’s Connection Troubleshoot tool helps to diagnose connectivity issues from the internet to Azure virtual machines.
The effective routes for a network interface in Azure give you the combined list of system and user-defined routes that are applied to the NIC.
B) False
Virtual machines in different Azure regions but within the same virtual network will need a Virtual Network Gateway or a similar mechanism such as VNet Peering or VPN Gateway to enable communication between them.
Azure virtual machines can be connected to, or removed from, Azure Virtual Networks both during their creation and after they have been provisioned.
D) Topology
The Topology feature of Azure Network Watcher allows visualization of network resources and their relationships, aiding troubleshooting of network structure and connectivity issues.
Azure Network Watcher provides VPN Diagnostics that enable administrators to troubleshoot connectivity issues for site-to-site VPN connections.
B) Missing a route to the internet in the route table
A common cause for a subnet’s inability to connect to the internet is a missing route to the internet, which can be resolved by verifying and adjusting the route table configurations as needed.
Azure Network Watcher is a cloud-based service that provides a suite of network monitoring and troubleshooting tools for Microsoft Azure. It helps to monitor, diagnose, and gain insights into the network performance and health of your virtual machines, subnets, and network security groups.
Azure Network Watcher can help to troubleshoot virtual network connectivity issues by providing diagnostic tools such as the Connectivity Check and the IP Flow Verify, which allow you to test and diagnose connectivity between virtual machines, subnets, and network security groups.
The Connectivity Check tool in Azure Network Watcher is a feature that allows you to test connectivity between a source virtual machine and a target virtual machine, subnet, or endpoint. It helps you to quickly identify if there is a connectivity issue between the source and target.
The IP Flow Verify tool in Azure Network Watcher is a feature that allows you to test connectivity between a source and target virtual machine or between a source virtual machine and an endpoint using the IP protocol. It helps you to diagnose the flow of traffic and identify where connectivity is being blocked.
You can use Azure Network Watcher to monitor network traffic by enabling the Traffic Analytics feature. This feature provides insights into traffic flow patterns, top talkers, and network security group (NSG) rule effectiveness. You can also configure NSG flow logs, which capture the IP traffic flowing through an NSG, and send them to Azure Storage, Log Analytics, or Event Hubs for analysis.
The Network Watcher Agent is an optional lightweight software component that can be installed on virtual machines in a virtual network. It allows you to collect packet captures, perform network latency tests, and monitor network health and performance. The Network Watcher Agent is useful for diagnosing complex connectivity issues and troubleshooting virtual network configurations.
The Network Performance Monitor is a feature in Azure Network Watcher that provides real-time network monitoring and diagnostic capabilities. It allows you to monitor the health and performance of your network infrastructure, including virtual machines, load balancers, and VPN gateways. You can use the Network Performance Monitor to detect and diagnose network issues, such as latency, packet loss, and connectivity issues.
The Next Hop tool in Azure Network Watcher allows you to identify the next hop for a given traffic flow between two virtual machines or between a virtual machine and an endpoint. It helps you to diagnose connectivity issues and identify where traffic is being dropped or routed incorrectly.
You can use Azure Network Watcher to troubleshoot VPN connections by using the VPN Troubleshoot feature. This feature provides a step-by-step troubleshooting guide that helps you diagnose and resolve issues with your virtual network gateway, connection, or on-premises network configuration.
The Network Topology tool in Azure Network Watcher provides a visual representation of your virtual network topology. It allows you to view the relationships between virtual machines, subnets, and network security groups, and to identify any misconfigurations or connectivity issues. You can use the Network Topology tool to troubleshoot virtual network connectivity and to ensure that your network is properly configured.
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