Firewalls and network security measures

In this video, you'll 
 learn about different types of firewalls. 
 These include hardware, 
 software, and cloud-based firewalls. 
 You'll also learn the difference between 
 a stateless and stateful firewall and 
 cover some of the basic operations 
 that a firewall performs. 
 Finally, you will explore how 
 proxy servers are used to 
 add a layer of security to the network. 
 
 
 
 
 
 
 
 
 
 A firewall is a network security device that 
 monitors traffic to and from your network. 
 It either allows traffic or it blocks 
 it based on a defined set of security rules. 
 A firewall can use port filtering, 
 which blocks or allows 
 certain port numbers to limit unwanted communication. 
 For example, it could have a rule 
 that only allows communications on port 
 443 for HTTPS or port 
 25 for email and blocks everything else. 
 These firewall settings will be determined by 
 the organization's security policy. 
 
 
 
 
 
 
 
 
 
 Let's talk about a few different kinds of firewalls. 
 A hardware firewall is considered the most 
 basic way to defend against threats to a network. 
 A hardware firewall inspects 
 each data packet before it's 
 allowed to enter the network. 
 A software firewall performs 
 the same functions as a hardware firewall, 
 but it's not a physical device. 
 Instead, it's a software program 
 installed on a computer or on a server. 
 If the software firewall is installed on a computer, 
 it will analyze all the traffic 
 received by that computer. 
 If the software firewall is installed on a server, 
 it will protect all the devices connected to the server. 
 A software firewall typically costs 
 less than purchasing a separate physical device, 
 and it doesn't take up any extra space. 
 But because it is a software program, 
 it will add some processing burden 
 to the individual devices. 
 
 
 
 
 
 
 
 
 
 Organizations may choose to use a cloud-based firewall. 
 Cloud service providers offer firewalls as 
 a service, or FaaS, for organizations. 
 Cloud-based firewalls are software firewalls 
 hosted by a cloud service provider. 
 Organizations can configure the firewall rules 
 on the cloud service provider's interface, 
 and the firewall will perform security operations on 
 all incoming traffic before 
 it reaches the organization’s onsite network. 
 Cloud-based firewalls also protect any assets or 
 processes that an organization 
 might be using in the cloud. 
 
 
 
 
 
 
 
 
 
 All the firewalls we have discussed can be 
 either stateful or stateless. 
 The terms "stateful" and "stateless" 
 refer to how the firewall operates. 
 Stateful refers to a class 
 of firewall that keeps track of 
 information passing through it 
 and proactively filters out threats. 
 A stateful firewall analyzes 
 network traffic for characteristics and 
 behavior that appear suspicious 
 and stops them from entering the network. 
 Stateless refers to a class 
 of firewall that operates based on 
 predefined rules and does not 
 keep track of information from data packets. 
 A stateless firewall only acts according to 
 preconfigured rules set by the firewall administrator. 
 The rules programmed by the firewall administrator tell 
 the device what to accept and what to reject. 
 A stateless firewall doesn't store analyzed information. 
 It also doesn't discover 
 suspicious trends like a stateful firewall does. 
 For this reason, stateless firewalls are considered 
 less secure than stateful firewalls. 
 
 
 
 
 
 
 
 
 
 A next generation firewall, or NGFW, 
 provides even more security than a stateful firewall. 
 Not only does an NGFW provide 
 stateful inspection of incoming and outgoing traffic, 
 but it also performs more 
 in-depth security functions like 
 deep packet inspection and intrusion protection. 
 Some NGFWs connect to 
 cloud-based threat intelligence services 
 so they can quickly update to 
 protect against emerging cyber threats. 
 
 
 
 
 
 
 
 Now you have a basic understanding 
 of firewalls and how they work. 
 We learned that firewalls can be hardware or software. 
 We also discussed the difference between 
 a stateless and stateful firewall 
 and the security benefits of a stateful firewall. 
 Finally, we discussed next generation firewalls 
 and the security benefits they provide. 
 Coming up, we'll learn more about virtual networks.