Microsoft AZ-700 Online Access

Here are the steps and explanations for ensuring that subnet4-3 can accommodate 507 hosts:

To determine the subnet size that can accommodate 507 hosts, you need to use the formula: number of hosts = 2^(32 - n) - 2, where n is the number of bits in the subnet mask1. You need to find the value of n that satisfies this equation for 507 hosts.

To solve this equation, you can use trial and error or a binary search method. For example, you can start with n = 24, which is the default subnet mask for Class C networks. Then, plug in the value of n into the formula and see if it is too big or too small for 507 hosts.

If you try n = 24, you get number of hosts = 2^(32 - 24) - 2 = 254, which is too small. You need to increase the value of n to get a larger number of hosts.

If you try n = 25, you get number of hosts = 2^(32 - 25) - 2 = 510, which is just enough to accommodate 507 hosts. You can stop here or try a smaller value of n to see if it still works.

If you try n = 26, you get number of hosts = 2^(32 - 26) - 2 = 254, which is too small again. You need to decrease the value of n to get a larger number of hosts.

Therefore, the smallest value of n that can accommodate 507 hosts is n = 25. This means that the subnet mask for subnet4-3 should be /25 or 255.255.255.128 in dot-decimal notation1.

To change the subnet mask for subnet4-3, you need to go to the Azure portal and select your virtual network. Then select Subnets under Settings and select subnet4-3 from the list2.

On the Edit subnet page, under Address range (CIDR block), change the value from /24 to /25. Then select Save2.

Here are the steps and explanations for ensuring that requests for wwwjelecloud.com from any of your Azure virtual networks resolve to frontdoor1.azurefd.net:

To use a custom domain with your Azure Front Door, you need to create a CNAME record with your domain provider that points to the Front Door default frontend host. A CNAME record is a type of DNS record that maps a source domain name to a destination domain name1.

To create a CNAME record, you need to sign in to your domain registrar’s website and go to the page for managing DNS settings1.

Create a CNAME record with the following information1:

Source domain name: wwwjelecloud.com

Destination domain name: frontdoor1.azurefd.net

Save your changes and wait for the DNS propagation to take effect1.

To verify the custom domain, you need to go to the Azure portal and select your Front Door profile. Then select Domains under Settings and select Add2.

On the Add a domain page, select Non-Azure validated domain as the Domain type and enter wwwjelecloud.com as the Domain name. Then select Add2.

On the Domains page, select wwwjelecloud.com and select Verify. This will check if the CNAME record is correctly configured2.

Once the domain is verified, you can associate it with your Front Door endpoint. On the Domains page, select wwwjelecloud.com and select Associate endpoint. Then select your Front Door endpoint from the drop-down list and select Associate2.

To minimize the risk of SNAT port exhaustion for your 100 virtual machines in subnet4-1, while ensuring minimal administrative effort, you can use an Azure NAT Gateway. This service provides scalable and resilient outbound connectivity for virtual networks, dynamically allocating SNAT ports to avoid exhaustion.

Navigate to the Azure Portal.

Search for “NAT gateways” and select it.

Click on “Create”.

Enter the following details:

Subscription: Select your subscription.

Resource Group: Select an existing resource group or create a new one.

Name: Enter a name for the NAT gateway (e.g., NATGateway-Subnet4-1).

Region: Select the region where your virtual network is located.

Click on “Next: Outbound IP”.

Choose whether to use existing public IP addresses or create new ones.

If creating new ones, click on “Add new” and configure the new public IP addresses.

Click on “Next: Subnet”.

Click on “Associate subnet”.

Select the virtual network that contains subnet4-1.

Select subnet4-1 from the list of subnets.

Click on “OK”.

Review your settings to ensure everything is correct.

Click on “Review + create” and then “Create”.

Azure NAT Gateway: This service provides outbound connectivity for virtual networks, dynamically allocating SNAT ports across all VM instances within a subnet. This dynamic allocation helps prevent SNAT port exhaustion, especially in scenarios with high outbound connection volumes12.

Dynamic SNAT Port Allocation: Unlike static allocation methods, NAT Gateway dynamically allocates SNAT ports based on demand, ensuring efficient use of available ports and reducing the risk of exhaustion2.

Step-by-Step SolutionStep 1: Create a NAT GatewayStep 2: Configure Outbound IP AddressesStep 3: Associate the NAT Gateway with Subnet4-1Step 4: Review and CreateExplanationBy following these steps, you can ensure that your 100 virtual machines in subnet4-1 can make the necessary API calls without running into SNAT port exhaustion, all while minimizing administrative effort.

To achieve the task of ensuring that virtual machines on VNET1 and VNET2 are included automatically in a DNS zone named contoso.azure, and that they can resolve the names of the virtual machines on either virtual network, you can follow these steps:

Step-by-Step Solution

Step 1: Create a Private DNS Zone

Navigate to the Azure Portal.

Search for “Private DNS zones” in the search bar and select it.

Click on “Create”.

Enter the DNS zone name as contoso.azure.

Select the appropriate subscription and resource group.

Click on “Review + create” and then “Create”.

Step 2: Link VNET1 and VNET2 to the DNS Zone

Go to the newly created DNS zone (contoso.azure).

Select “Virtual network links” from the left-hand menu.

Click on “Add”.

Enter a name for the link (e.g., VNET1-link).

Select the subscription and virtual network (VNET1).

Enable auto-registration to ensure that VMs are automatically registered in the DNS zone.

Click on “OK”.

Repeat the process for VNET2.

Step 3: Configure DNS Settings for VNET1 and VNET2

Navigate to VNET1 in the Azure Portal.

Select “DNS servers” under the “Settings” section.

Ensure that the DNS server is set to “Default (Azure-provided)”.

Repeat the process for VNET2.

Step 4: Verify Name Resolution

Deploy a virtual machine in VNET1 and another in VNET2.

Connect to the virtual machines using Remote Desktop Protocol (RDP) or Secure Shell (SSH).

Test name resolution by pinging the VM in VNET2 from the VM in VNET1 using its hostname (e.g., ping .contoso.azure).

Explanation

Private DNS Zone: This allows you to manage and resolve domain names in a private network without exposing them to the public internet.

Virtual Network Links: Linking VNET1 and VNET2 to the DNS zone ensures that VMs in these networks can register their DNS records automatically.

Auto-registration: This feature automatically registers the DNS records of VMs in the linked virtual networks, simplifying management.

DNS Settings: Using Azure-provided DNS ensures that the VMs can resolve each other’s names without additional configuration.

By following these steps, you ensure that virtual machines on VNET1 and VNET2 are included automatically in the DNS zone contoso.azure and can resolve each other’s names seamlessly.