In the output of iptables -L -n is the line ACCEPT all - - 10.69.70.5 0.0.0.0/0 listed under the INPUT chain. What does this line mean?

Question

Options

• AThat all traffic from 0.0.0.0/0 to 10.69.70.5 is explicitly allowed
• BTCP traffic to 10.69.70.5 with all of the TCP flags is allowed
• CAll traffic from 10.69.70.5 to anywhere is allowed
• DThe ACCEPT chain is responsible for all traffic from 10.69.70.1 to 0.0.0.0

• A
  3% (1)
• B
  7% (2)
• C
  80% (24)
• D
  10% (3)

Explanation

Option C is correct because in iptables -L -n output, the columns are ordered target, protocol, options, source, destination - so 10.69.70.5 is the source and 0.0.0.0/0 (meaning "any address") is the destination. This INPUT chain rule therefore accepts all protocol traffic from host 10.69.70.5 going to anywhere.

Why the distractors fail:

• A reverses the source/destination columns - 0.0.0.0/0 is the destination, not the source, so it does not describe traffic from 0.0.0.0/0 to 10.69.70.5.
• B is wrong on two counts: the protocol field shows all, not TCP, and no TCP flags are specified anywhere in this rule.
• D confuses ACCEPT as a chain name (it's a target/action), invents the IP 10.69.70.1 which doesn't appear in the rule, and misreads the field order entirely.

Memory tip: Memorize the column order as "T-P-O-S-D" (Target, Protocol, Opt, Source, Destination) - think "The Protocol Often Sends Data". When you see a rule, slot each value into that template left-to-right and the meaning becomes unambiguous.

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