Firewall

hello and this is sunny welcome back and Internet is a private network which is heavily protected by many different networking devices such as a router firewall proxy server DMZ honeynet IPs and IDs this diagram is an overly simplified version of the reality I try to pull these devices together in a reasonable order only for teaching and learning purpose today my topic is firewall firewalls protect a network from external threats using a variety of methods in this video I will talk about five major functions number one port filtering portal filtering is also called port blocking a port number means a certain application different applications use different port numbers portal filtering is a function that allows or denies a certain applications by opening all closing ports opening port 80 for example means web pages can go through the firewall 25 for sending email and a 21 for FTP and etc if the firewall is set up to block posts 7 19 and 53 for example it means the firewall will block application using these port numbers number two function Mac filtering MAC address is media access control address is a unique identifier assigned to a device network interface card or NIC it is a devices physical address this option is useful because the MAC address of a specific NIC never changed number three function is IP filtering IP filtering is also called packet filtering it blocks the packets based on layer 3 IP address IP filtering will block incoming or outgoing packet from a particular IP address or range of IP addresses number 4 function of the firewall is accounting the filtering and is also called information filtering in the most general sense counting the filtering can include a filtering application such as emails web page in a narrow sense counting the filtering is a blocking websites by a matching strings of characters such as hate violence open ography when the streams match the content is not allowed through this function is a similar to some parental control programs the four functions are just mentioned above are simple static or stateless filtering each packet is examined independently based on a different variables and with no reference to any preceding pakis that may help past the firewall the last function I'm going to talk about is a done Amica filtering or some people called stateful filtering dynamic or stateful filtering is the most comprehensive inspection it's like going through u.s. airport security you must have a valid ID to match the name on your boarding pass you will be examined and scanned from head to toe I'm glad they didn't ask me to take my head off and put in the tree from the perspective the OSI model dynamic filtering is like checking packets from layer to to layer seven the process of a dynamic filtering does not only involve inspection our header information such as source and destination IP addresses and port numbers but also includes the close inspection is contents up to the application layer but keep in mind dynamic inspection is not is not a simple sum of all static or stateless inspections the most important feature of stateful or dynamic inspection is that all packets are examined as a string as a string which means the decision on whether to pass a packet depends on what packets have already been through the firewall to put it simply packets are examined as a whole not as a simple sum of its parts the stateful or dynamic inspection also analyzes incoming packet for is authenticity in order to ensure that a packet is not altered during the transmission in summary static or state lists firewalls make decisions based on a variables like IP address MAC address or port address dynamic or stateful firewalls make decisions based on a whole picture I hope this video would be helpful and not confusing thank you very much and I'll see you next time [Music]

Channel: Sunny Classroom

Views: 63,304

Rating: 4.9561725 out of 5

Keywords: sunny sun sunnysunkansas sunnyclassroom, networking, cybersecurity, security+, networking +, cyber threats, cyber defense, IoT, Wi-Fi security, Sunnysunkansas, Sunny classroom, firewall, stateful and stateless filtering, dynamic vs static filtering, fort filtering, port blockiing, mac filtering, packet filtering, content filtering, stafeful inspection, stateless inspection, dynamic inspection

Id: RV2QznoyEBU

Length: 7min 19sec (439 seconds)

Published: Sun Jan 07 2018