Application Security Groups (ASG)
- ASGs help to manage security of virtual machines by grouping them according to the applications that run on them

- So lets try this sample
- Create a virtual with 4 subnets
- subnet1
- subnet2
- subnet3
- subnet4

- Create 3 ASG (WebServers, AppServers, DbServers)

- Now lets create a NSG which allows
- traffic from anywhere in to webservers on port 80,22
- traffic from webservers to appserver on port 8080
- traffic from appservers to dbservers on port 3306/1433
- allow ping with same restrictions
- deny the rest of the traffic

- Create 3 linux vms in any subnets of your choice
- Create a linux vm for webserver functionality and once the vm is created then navigate to the networking section and configure this vm as webserver

- Create one more linux vm in any subnet and configure this vm as AppServer in the ASG Section
- Create one more linux vm in any subnet and configure this vm as DbServer in Asg section
- for the all vms use the same network security group
- Create a linux vm for webserver functionality and once the vm is created then navigate to the networking section and configure this vm as webserver
- Create a virtual with 4 subnets
Scenario:
- Create two vnets in two different resource groups (two different locations) as shown below

- Create a resource group

- If we create vms in two different vnets they can communicate over public ip but that uses internet. Our requirement is to enable communication b/w two vnets over private ip addresses
- Enabling private communication b/w virtual networks in Azure is referred as vnet peering
- Now lets create one vm in network1 and one vm in network2

- Once the vm’s are created, try to login into one vm and then try to login from that vm in network to network2 using private ip address

- There is no private connectivity. Now lets navigate to the network1 and select peering

- Now lets try to login back using private ip address which failed earlier

- Ideally you should make changes in the nsg to allow the communication from the cidr range of network1 in network and viceversa
