A layer-4 firewall (a device that can look at all protocol headers up ...
Since it is a layer 4 firewall it cannot block application layer protocol like HTTP.
View all questions of this test
A layer-4 firewall (a device that can look at all protocol headers up ...
Layer-4 Firewall Restrictions
A layer-4 firewall can examine all protocol headers up to the transport layer, including TCP and UDP packets. However, there are certain limitations to what a layer-4 firewall can do.
Cannot Block Entire HTTP Traffic During 9:00PM and 5:00AM
A layer-4 firewall cannot block entire HTTP traffic during a specific time range, such as 9:00PM to 5:00AM. This is because HTTP traffic is carried over TCP, and a layer-4 firewall cannot distinguish between different types of HTTP traffic. Therefore, it cannot block HTTP traffic based on time of day.
Cannot Block All ICMP Traffic
A layer-4 firewall can block ICMP traffic, but it cannot block all ICMP traffic. ICMP is used for network troubleshooting and error reporting, and blocking all ICMP traffic can cause network problems. Therefore, a layer-4 firewall should only block specific types of ICMP traffic that are known to be malicious.
Cannot Stop Incoming Traffic from a Specific IP Address but Allow Outgoing Traffic to the Same IP Address
A layer-4 firewall cannot stop incoming traffic from a specific IP address but allow outgoing traffic to the same IP address. This is because the firewall cannot distinguish between incoming and outgoing traffic based on IP address alone. Therefore, a layer-4 firewall can only block traffic based on the type of protocol and port number.
Cannot Block TCP Traffic from a Specific User on a Multi-User System During 9:00PM and 5:00AM
A layer-4 firewall cannot block TCP traffic from a specific user on a multi-user system during a specific time range, such as 9:00PM to 5:00AM. This is because a layer-4 firewall cannot distinguish between different users on a multi-user system based on TCP traffic alone. Therefore, a layer-4 firewall can only block traffic based on the type of protocol and port number.
Conclusion
In conclusion, a layer-4 firewall has certain limitations, and it cannot perform all the functions that are required for network security. Therefore, it is important to use multiple layers of security, including firewalls, intrusion detection systems, and other security measures to ensure the security of the network.
To make sure you are not studying endlessly, EduRev has designed Computer Science Engineering (CSE) study material, with Structured Courses, Videos, & Test Series. Plus get personalized analysis, doubt solving and improvement plans to achieve a great score in Computer Science Engineering (CSE).