A layer-4 firewall (a device that can look at all protocol headers up to the transport layer) CANNOT
1
block entire HTTP traffic during 9:00 PM and 5:00 AM
2
block all ICMP traffic
3
stop incoming traffic from a specific IP address but allow outgoing traffic to the same IP address
4
block TCP traffic from a specific user on a multi-user system during 9:00 PM and 5:00 AM