# Security

- Can I Change the Security Group of an ECS?
- How Many Security Groups Can I Create?
- How Do I Configure a Security Group for Multi-Channel Protocols?
- How Many Firewalls Can I Create?
- Does a Security Group Rule or a Firewall Rule Immediately Take Effect for Existing Connections After It Is Modified?
- Which Security Group Rule Has Priority When Multiple Security Group Rules Conflict?

Parent topic: FAQs