Managing security groups
Security groups can be managed using the Neutron CLI or the Horizon dashboard. From within the Neutron command-line client, a number of commands can be used to manage security groups, including:
security-group-create
security-group-delete
security-group-list
security-group-rule-create
security-group-rule-delete
security-group-rule-list
security-group-rule-show
security-group-show
security-group-update
From the Horizon dashboard, security groups and rules are managed from the Compute | Access & Security panel.
Using CIDR to control traffic
Understanding how to properly subnet networks using the Classless Inter-Domain Routing (CIDR) notation is important for controlling access to instances. Using the wrong CIDR notation in a security group rule can expose your application and your environment to the Bad Guys™, a situation we'd like to prevent.
The following are some examples of networks using CIDR notation:
0.0.0.0/0
– This would allow traffic from all IP...