Explanation:

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 name 2. 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:

Explanation:

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 name 2. 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:

Explanation:

BOX1: Review the output of the route print command on the client computer. A Windows VPN connection is a point-to-site connection that allows a client computer to connect to an Azure virtual network gateway using IKEv2 or SSTP protocols1. To troubleshoot Windows VPN connectivity issues, you need to check the configuration and status of the VPN client on the client computer.

One of the common problems that can cause Windows VPN connectivity issues is incorrect routing configuration on the client computer1. The client computer needs to have a route that directs the traffic destined for the target subnet in Azure to the VPN interface. If the route is missing or incorrect, the traffic will not reach the Azure virtual network gateway.

To check the routing configuration on the client computer, you can use the route print command in a command prompt window. This command displays the routing table of the client computer, which shows the destination network, the gateway address, and the interface for each route2. You can compare the output of this command with the expected routes for your VPN connection.

For example, if your target subnet in Azure is 10.0.0.0/24 and your VPN interface has an IP address of 172.16.0.1, you should see a route like this in the output of route print: Destination Network | Gateway Address | Interface 10.0.0.0/24 | On-link | 172.16.0.1

This route means that any traffic destined for 10.0.0.0/24 will be sent directly to the VPN interface (On-link) with an IP address of 172.16.0.1.

If you do not see this route or see a different gateway address or interface, you need to correct the routing configuration on the client computer. You can use the route add command to add a new route or use the route change command to modify an existing route 2.

Box 2: Download the VPN client package and install it on the client computer

A Windows VPN connection is a point-to-site connection that allows a client computer to connect to an Azure virtual network gateway using IKEv2 or SSTP protocols1. To establish a Windows VPN connection, you need to install a VPN client package on the client computer that contains the configuration files and certificates required for the connection1. One of the common problems that can cause Windows VPN connectivity issues is missing or outdated VPN client package on the client computer1. The VPN client package may be missing if it was not installed properly or deleted accidentally. The VPN client package may be outdated if the Azure virtual network gateway configuration has changed since the package was downloaded.

To resolve this problem, you need to download the latest VPN client package from the Azure portal and install it on the client computer1.

To download the VPN client package, follow these steps:

✑ Go to the Azure portal and select your virtual network gateway.

✑ On the Overview page, click Point-to-site configuration.

✑ On the Point-to-site configuration page, click Download VPN client.

✑ Select the appropriate version of Windows for your client computer and click Download.

✑ Extract the contents of the downloaded ZIP file to a folder on your client computer.

✑ Run the executable file in the folder to install the VPN client package.

Explanation:

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.

Explanation:

BOX 1: Run the command: nslookup -type=a www.contoso.com 8.8.8.8 nslookup is a command-line tool that queries DNS servers for information about domain names and IP addresses. It can be used to troubleshoot DNS issues and verify DNS configurations1.

The -type option specifies the type of DNS record to query. The -type=a option queries for A records, which map domain names to IPv4 addresses1. The www.contoso.com argument specifies the domain name to query. The 8.8.8.8 argument specifies the DNS server to use for the query, which is a public DNS server provided by Google2.

By running this command, you can verify if the Azure Public DNS zone is configured according to the requirements by checking if the A record for www.contoso.com matches the expected IPv4 address. If the A record is missing or incorrect, you can use the Azure portal, PowerShell, or Azure CLI to create or update it in your DNS zone3.

Box2: Create NS records

NS (Name Server) records are used to delegate a domain or subdomain name to a set of authoritative DNS servers, which can provide information about that domain. In this scenario, there appears to be an issue with resolving the domain in question via public DNS lookup since it’s only resolving locally on one server and not across all networks. By creating NS records for the domain, authoritative nameservers will be identified and designated as responsible for providing accurate information about the specific zone. This will ensure your domain is properly distributed on various different network zones and help users globally reach your website without any delays or connectivity problems. Alternatively, SRV (Service locator) record is used when you have multiple servers offering similar services such as email or SIP but want to use a weight system indication greater trustworthiness/proximity of datacenters within providers dns infrastructure. And SOA (Start Of Authority) – indicates who in control of the DNS zone and provides other related information such as the serial number and default TTL values. Therefore, option A. Create NS records would be the best solution for resolving public DNS lookup issues in this scenario. References: – "NS record," Microsoft Docs, accessed March 27, 2023. [Online]. Available: https://docs.microsoft.com/en-us/windows-server/networking/dns/deploy/create-a-dns-record-for-domain-access#ns-record – "SRV record," Cloudflare Help Center, accessed March 27, 2023. [Online]. Available: https://support.cloudflare.com/hc/en-us/articles/216672888-SRV-Record-Setup – "SOA record," DigitalOcean Product Documentation, accessed March 27, 2023. [Online]. Available: https://www.digitalocean.com/community/tutorials/how-to-manage-dns-using-the-digitalocean-control-panel#start-of-authority-record

Explanation:

Connection: VNet1-VNet4 Parameters are: AllowGatewayTransit: Enabled

Connection: VNet4-VNet1 Parameters are: UseRemoteGateways: Enabled

To resolve the connectivity issues for VM1 to Contoso Suites, you need to configure the peering connections between VNet1 and VNet4 correctly. The peering connection from VNet1 to VNet4 should have the AllowGatewayTransit parameter enabled, which allows VNet1 to use the virtual network gateway in VNet4 as a transit point for traffic. The peering connection from VNet4 to VNet1 should have the UseRemoteGateways parameter enabled, which allows VNet4 to use the remote gateway in VNet1 for traffic destined to Contoso Suites. The IP Allocation parameter should be set to Dynamic for both peering connections, which allows Azure to assign IP addresses from the address space of the peered virtual network. The ServiceEndpoint parameter should be set to None for both peering connections, as there is no need to enable service endpoints for this scenario.