Alice is a network security engineer in a small size company. The database and web servers for her company are running on Amazon AWS cloud platform. Her boss asked her to research information on firewalls. They need a firewall 

1) that allows for more generic statements instead of creating specific rules; 

2) that keeps a record of the state of a connection between an internal endpoint and an external device; 

3) that combines several security functions including packet filtering, antispam, anti-phishing, antispyware, intrusion protection, and web filtering; and 

4) that can protect both the database and web servers cost-effectively. According to the knowledge you learnt in this unit, please explain what features the firewall expects.