Which statement describes the characteristics of packet-filtering and stateful firewalls as they relate to the OSI model?
- A packet-filtering firewall uses session layer information to track the state of a connection, whereas a stateful firewall uses application layer information to track the state of a connection.
- Both stateful and packet-filtering firewalls can filter at the application layer.
- A packet-filtering firewall typically can filter up to the transport layer, whereas a stateful firewall can filter up to the session layer.
- A stateful firewall can filter application layer information, whereas a packet-filtering firewall cannot filter beyond the network layer.
Explanation: Packet filtering firewalls can always filter Layer 3 content and sometimes TCP and UDP-based content. Stateful firewalls monitor connections and thus have to be able to support up to the session layer of the OSI model.