Online AZ-720 Questions Video

Box 1 =  Use IP flow verify.

IP flow verify is a feature of Azure Network Watcher that checks if a packet is allowed or denied to or from a virtual machine. It can help diagnose connectivity issues caused by network security groups, user-defined routes, or Azure Virtual Network Manager rules1. IP flow verify can also return the name of the rule that denied the packet, which can be useful for troubleshooting2.

Connection troubleshoot is another feature of Azure Network Watcher that helps reduce the time to diagnose and resolve network connectivity issues. However, it can only test TCP or ICMP connections from certain Azure resources, such as virtual machines, Azure Bastion instances, or application gateways3. Connection troubleshoot can also detect issues such as high VM CPU utilization, DNS resolution failures, or inability to open a socket at the specified source port3.

In this scenario, you need to collect the required logs for the SharePoint workload in VNet2. Since you are not testing a specific TCP or ICMP connection, but rather checking if packets are allowed or denied by any network configuration, IP flow verify is more suitable than connection troubleshoot. You can use IP flow verify to check the direction, protocol, local IP, remote IP, local port, and remote port of the packets and see which rule is blocking them12.

To use IP flow verify, you need to enable a network watcher in the same region as the virtual machines you want to troubleshoot. Then you can use the Azure portal, PowerShell, or Azure CLI to run IP flow verify and get the results24.

Box 2 =  Use Traffic analytics

To troubleshoot issues related to the SharePoint workload in VNet2, we can use Traffic Analytics. It is a networking monitoring solution that uses Network Watcher to analyze and report on traffic flows in your Azure virtual network. With Traffic Analytics, you could see information about the traffic flow patterns and security concerns detected across Azure subscriptions using network security group (NSG) flow logs. IP Flow Verify is used to verify if packets are flowing as expected between two endpoints within an Azure virtual network or between a public IP address and an endpoint inside an azure virtual network. But it doesn't provide visibility into overall traffic patterns or identify potential security threats. Connection Troubleshoot can be used when you have connectivity problems while interacting with a specific instance of a resource type being served out from Microsoft datacenters over Internet, but for troubleshooting SharePoint workloads related issue which might not necessarily correspond to internet routing/connectivity problems this may not apply.

Box 1: Deploy an Azure virtual machine (VM) that hosts a DNS service.

In the given scenario, CosmosDB1 is an on-premises database, and you need to make it accessible by host name using VNet1. To achieve this, you should deploy an Azure virtual machine that hosts a DNS service. This will allow you to configure custom DNS settings for VNet1, enabling the resolution of the on-premises database's host name. Reference:

Box 2: Configure DNS conditional forwarding in the on-premises DNS infrastructure.

In the given scenario, you need to resolve the connectivity issue with the on-premises database named CosmosDB1, and it must be accessible by hostname from the on-premises environment. To achieve this, you should configure DNS conditional forwarding in the on-premises DNS infrastructure. DNS conditional forwarding allows you to specify that DNS queries for a specific domain (in this case, the Azure Cosmos DB) are forwarded to a specific DNS server or set of servers. This ensures that the on-premises environment can resolve the hostname of CosmosDB1 by forwarding the DNS queries to the appropriate DNS server responsible for that domain. References: 1. 2.

Box 1: Verify that VNet1 is configured to use the built-in Azure resolution

As mentioned in the scenario, you need to troubleshoot and resolve the reverse DNS lookup issues. Reverse DNS lookup is a process of resolving an IP address to a host name2. For example, if you have a virtual machine with an IP address of 10.0.0.4 and a host name of vm1.contoso.com, you can use reverse DNS lookup to find the host name from the IP address.

One way to perform reverse DNS lookup in Azure is to use the built-in Azure resolution. The built-in Azure resolution is a feature that allows reverse DNS lookup (PTR DNS queries) for virtual machine IP addresses by default1. This feature works for both IPv4 and IPv6 addresses, and it supports both public and private IP addresses. The built-in Azure resolution uses the host name of the virtual machine as the reverse DNS record.

To use the built-in Azure resolution, you need to configure your virtual network to use the default Azure-provided DNS servers. These are the DNS servers that are automatically assigned to your virtual network when you create it3. You can verify or change the DNS server settings of your virtual network using the Azure portal, PowerShell, CLI, or REST API.

To verify that VNet1 is configured to use the built-in Azure resolution using the Azure portal, follow these steps:

• In the Azure portal, navigate to the Virtual Network resource.
• Select DNS servers under Settings.
• Check if Default (Azure-provided) is selected under DNS servers. If not, select it and click Save to apply the changes.

After configuring your virtual network to use the built-in Azure resolution, you can test the reverse DNS lookup using tools such as nslookup or dig. For example, you can use the following command to perform a reverse DNS lookup for an IP address of 10.0.0.4:

nslookup -type=PTR 10.0.0.4

The output should show the host name of the virtual machine that has that IP address.

Box 2: Create an in-addr.arpa private DNS zone and link it to VNet1, VNet2, and VNet3.

Reverse DNS lookup issues are related to resolving IP addresses to their corresponding hostnames. In the given scenario, the issue is with reverse DNS lookups for the resources in the three virtual networks. Creating an in-addr.arpa private DNS zone and linking it to VNet1, VNet2, and VNet3 would ensure that the reverse DNS lookups can be resolved correctly across all three virtual networks. Reference: 1. Azure Private DNS: 2. Reverse DNS lookup in Azure:

To resolve the VM2 routing issue, you should modify the IP configuration setting of the Azure network interface resource of VM2. This will ensure that VM2 can communicate with other resources in the virtual network.

Troubleshooting connectivity problems between Azure VMs involves several steps such as checking whether NIC is misconfigured, whether network traffic is blocked by NSG or UDR, whether network traffic is blocked by VM firewall, whether VM app or service is listening on the port and whether the problem is caused by SNAT1.