AWS SECURITY GROUPS

 SECURITY GROUPS:

A security group acts as a virtual firewall that controls the traffic for one

or more instances.

When you launch an instance, you associate one or more security groups

with the instance.

You add rules to each security group that allow traffic to or from its

associated instances.

You can modify the rules for a security group at any time; the new rules

are automatically applied to all instances that are associated with the

security group.

Click on Security groups section under NETWORK & SECURITY from

the left pane.

Click on security group and select your instance 

Choose edit inbound rules to edit the security group.

Select specific rule which is required, I selected HTTP to open 80 port on the security group.

You can either select Custom TCP rule or Custom UDP rule and specify the port which you want to open.

Or you can specify TCP or UDP and specify a range of IP addresses (20-100).

Then select source IP address from by selecting Source drop down list either Custom IP, Anywhere or My IP then click create.

Then click on Save Rules.

The same will applies to Outbound as well, where we can restrict either by Port or by IP address.

CHANGING OR ADDING SECURITY GROUPS TO YOUR EXISTING INSTANCES:

Click the instance from Instance tab and select the instance, then click on Actions.

Click on Security and select  Change security Groups

By Clicking on ADD SECURITY GROUP , You can change the security group 

Click on save option to change and save your security group.