Azure VNet contd..

• Lets understand about the virtual machines to be created in subnets

• When we create a vm in the subnet the vm will recieve the private ip address from the subnets cidr range

• To connect vm to the subnet a network interface card is create which connects vm to the subnet.

• NIC recieves a private ip address

• Public IP address can be assigned to the NIC (optional). Steps included are

  • Public IP Address resource is created
  • Public IP address is associated with NIC
  • When you access the Public IP the traffic/nw packets will be forwarded to nic.

• Azure gives option to choose the private ip address in the subnet address space and assign automatically by azure. Private Ip addresses are free of cost

• Azure Public IP assigns a random public from the pool of public ip addresses available in Azure and the Azure Public IP is charged

• Azure Public IP Address has two plans (SKU)

  • Dynamic
  • Static

• Lets create a virtual network and for that lets try to follow the following architecture

• We will be not creating Application Gateway subnet and Active Directory subnet

• Generally when we create a subnet with 8 bits for host ids then the formula is 2^n-2

  • x.x.x.0: Network id/Address
  • x.x.x.255: Broadcast address

• In the case of azure we have 3 more reservations i.e. 2^n-5

  • x.x.x.0: Network id/Address
  • x.x.x.255: Broadcast address
  • x.x.x.1: Reserver by azure for default gateway
  • x.x.x.2, x.x.x.3: Reserver by Azure to map the Azure DNS IPs to VNET space

• Lets continue the network creation

• In Azure the smallest subnet supported is /29 and the largest subnet is /8

• Now lets try to create a Windows Server in the Management subnet

• We want use this windows machine from our network so we should be able to login from our system, so windows machine needs a public ip address to communicate

• Now lets login into the windows vm created mstsc -v publicip

• Now lets create one more windows server in the web subnet without public ip

• Machine in the management subnet can help us to reach to web subnet machine

• So, the machines which are have public ip addresses and help us to connect to machines with only private ip addresses are referred as Bastion Hosts or Jump Box

• In Azure when we create a vnet it belongs to region and subnet also belongs or is scoped to a region. There are some regions in Azure where zones are supported even in that case subnet is scoped to a region. With in one subnet you can have resources created in multiple zones