In a packet-filtering firewall, which rule causes the packet to be dropped without diagnostic message?

In a packet-filtering firewall, which rule causes the packet to be dropped without diagnostic message?

• A. Allow: allow packet to pass
• B. Drop: drops the packet without any diagnostic message to the packet source host
• C. Deny: Do not let the packet pass, but notify the source host
• D. Reject: Do not let the packet pass and send an ICMP error

Answer: (B)

In packet-filtering firewalls, actions determine how a matching packet is treated: it can be allowed to pass, dropped silently, denied with a notification, or rejected with an ICMP error. The option that drops the packet without any diagnostic message is the silent drop. When a packet hits a drop rule, the firewall simply discards it and sends no reply or error back to the sender, which makes the source unaware that the packet was blocked. This contrasts with rejecting, which would send an ICMP error back, and with deny/notify, which implies some form of feedback to the source. Allow simply forwards the packet.

In packet-filtering firewalls, actions determine how a matching packet is treated: it can be allowed to pass, dropped silently, denied with a notification, or rejected with an ICMP error. The option that drops the packet without any diagnostic message is the silent drop. When a packet hits a drop rule, the firewall simply discards it and sends no reply or error back to the sender, which makes the source unaware that the packet was blocked. This contrasts with rejecting, which would send an ICMP error back, and with deny/notify, which implies some form of feedback to the source. Allow simply forwards the packet.