Stateful packet inspection
Presentation Layer.
it may be network layer or transport layer.. it depends on the design of the firewall.. also depends on the requirement specification..
A firewall generally works at layer 3 and 4 of the OSI model. Layer 3 is the Network Layer where IP works and Layer 4 is the Transport Layer, where TCP and UDP function. Many firewalls today have advanced up the OSI layers and can even understand Layer 7 - the Application Layer.
Network Layer
A firewall generally works at layer 3 and 4 of the OSI model. Layer 3 is the Network Layer where IP works and Layer 4 is the Transport Layer, where TCP and UDP function. Many firewalls today have advanced up the OSI layers and can even understand Layer 7 - the Application Layer.
Transport layer .....
Data Link Layer
presentation layer
The layer of the OSI model provides connectivity and path selection between two end systems where routing occurs in the network layer. The layer of the OSI model provides network services to processes in electronic mail and file transfer programs is application.
Layer 2 - The Data Link Layer Layer 2 of the OSI model provides error-detection capability
Network Layer