How DNS WorksTo properly understand the various DNS services and features available in Azure, it is first necessary to understand how the domain name system works. In particular, it is important to understand the different roles played by recursive and authoritative DNS servers, and how a DNS query is routed to the correct DNS name…
Port Number Groups – 100-150 Exam Guide
Port Number Groups (26.4.3) The Internet Assigned Numbers Authority (IANA) is the standards organization responsible for assigning various addressing standards, including the 16-bit port numbers. The 16 bits used to identify the source and destination port numbers provides a range of ports from 0 through 65535. The IANA has divided the range of numbers into…
Configure name resolution and load balancing
Skill 4.3: Configure name resolution and load balancing Humans work with names, but computers prefer IP addresses. Fundamentally, DNS is about mapping names to IP addresses, making name-based rather than IP-based networking possible. Simplifying somewhat, a client makes a DNS query containing a domain name and receives a response containing the IP address for that…
Configure private endpoints for Azure services
Configure private endpoints for Azure servicesPrivate endpoints take the concept of service endpoints one step further. In the same scenario of a VM in subnet0 trying to communicate with a storage account, in addition to using a pri- vate IP address as the source IP address, the destination IP address will also be private. Private…
Configure service endpoints for Azure services
Configure service endpoints for Azure servicesBy default in Azure, PaaS services are accessible using a public endpoint that resolves to a public IP address. When a VM in a subnet accesses this service, for example a storage account, the network and routing from the VM translates the source IP to the IP of the VNet…
Port Numbers – 100-150 Exam Guide
Port Numbers (26.4) This section covers how both TCP and UDP use port numbers to identify the proper application layer process. Multiple Separate Communications (26.4.1) As you have learned, there are some situations in which TCP is the right protocol for the job, and other situations in which UDP should be used. No matter what…
Deploy and configure Azure Bastion Service
Deploy and configure Azure Bastion ServiceGenerally, you connect to remote virtual machines with either RDP or SSH. To do so, you either need to assign a public IP address (with the RDP/SSH port exposed) to the VM to which you are trying to connect, or you need to provision an additional jump server, assign a…
UDP Overview – 100-150 Exam Guide
UDP Overview (26.3) The reliability and flow control features provided by TCP come with additional overhead related to the connection establishment and tracking whether or not segments were received. UDP is a transport layer protocol that is used when this kind of overhead creates unnecessary delay. For example, transaction-based protocols such as DNS or DHCP,…
Create and configure an application security group
Create and configure an application security groupApplication security groups (ASGs) are separate objects that you create in your Azure subscrip- tion. You can think of an ASG like a group object in an identity system–members of the group have the permissions and access that are assigned to the group. ASGs work in a similar way—…
TCP Overview – 100-150 Exam Guide
TCP Overview (26.2) As previously mentioned, both TCP and UDP are transport layer protocols. It is up to the developer to determine which of these protocols best matches the requirements of the application being developed. TCP establishes a connection proving reliability and flow control. TCP Features (26.2.1) This section gives more details about what TCP…