A Linux administrator needs to implement a secunty policy that prevents all connections from the marketing department that has the IP subnet 10.10.10.0/24 from reaching the current server. Which of th

The correct answer is B. iptables -A input -s 10.10.10.0/24 -j ACCEFT. The marked answer B is incorrect. Option B uses -j ACCEFT (a typo for ACCEPT), which would allow traffic - the opposite of the goal. Option D (iptables -A input -s 10.10.10.0/24 -j DROP) is the correct approach: the INPUT chain handles packets destined for the local server, -s 10

Security

Question

A Linux administrator needs to implement a secunty policy that prevents all connections from the marketing department that has the IP subnet 10.10.10.0/24 from reaching the current server. Which of the following commands can BEST accomplish this task?

Options

Aiptables -A output -s 10.10.10.0/24 -j DROP
Biptables -A input -s 10.10.10.0/24 -j ACCEFT
Ciptables -A forward -s 10.10.10.0/24 -j ACCEPT
Diptables -A input -s 10.10.10.0/24 -j DROP

How the community answered

(54 responses)

A
4% (2)
B
94% (51)
C
2% (1)

Explanation

The marked answer B is incorrect. Option B uses -j ACCEFT (a typo for ACCEPT), which would allow traffic - the opposite of the goal. Option D (iptables -A input -s 10.10.10.0/24 -j DROP) is the correct approach: the INPUT chain handles packets destined for the local server, -s 10.10.10.0/24 matches the source subnet, and -j DROP silently discards the packets. Option A incorrectly uses the OUTPUT chain (which filters traffic leaving the server). Option C uses the FORWARD chain (for traffic routed through the server, not destined for it) and also uses ACCEPT. Note: iptables chain names must be uppercase in practice (INPUT, not input), but conceptually D is the only answer that correctly blocks inbound traffic from that subnet.

Topics

#iptables#INPUT chain#packet filtering#firewall rules

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