The following is the description of a partial configuration of a router. The correct description of this configuration is: `` [HUAWEI]acl number 2001 [HUAWEI-acl-basic-2001]rule 0 permit source…

Question

[HUAWEI]acl number 2001
[HUAWEI-acl-basic-2001]rule 0 permit source 1.1.1.1 0
[HUAWEI-acl-basic-2001]rule 1 deny source 1.1.1.0 0
[HUAWEI-acl-basic-2001]rule 2 permit source 1.1.0.0 0.0.255.255
[HUAWEI-acl-basic-2001]rule 3 deny

Options

• AThe data packet whose source address is 1.1.1.1 matches the first ACL statement rule 0, and the matching rule is Allow.
• BThe data packet whose source address is 1.1.1.3 matches the third ACL statement rule 2, and the matching rule is Deny.
• CThe data packet whose source address is 1.1.1.4 matches the fourth ACL statement rule 3, and the matching rule is Allow.
• DThe data packet whose source address is 1.1.1.2 matches the second ACL statement rule 1, and the matching rule is Allow.

• A
  78% (54)
• B
  3% (2)
• C
  6% (4)
• D
  13% (9)

Explanation

Option A is correct because the wildcard mask 0 (all zeros) in rule 0 permit source 1.1.1.1 0 means exact match only - packet source 1.1.1.1 hits this rule first and is permitted, since ACLs process rules top-to-bottom and stop at the first match.

Option B is wrong because 1.1.1.3 does not match rule 0 (not exactly 1.1.1.1) or rule 1 (not exactly 1.1.1.0), but does match rule 2 (1.1.0.0 0.0.255.255 covers all of 1.1.x.x) - the action is permit, not deny.

Option C is wrong because 1.1.1.4 is also covered by rule 2's range (1.1.0.0/0.0.255.255), so it matches rule 2 with a permit - it never reaches rule 3.

Option D is wrong because 1.1.1.2 is not exactly 1.1.1.0, so it skips rule 1 entirely and matches rule 2 (permit) - rule 1 is also a deny, not allow.

Memory tip: Think of wildcard 0 as "freeze this octet - must match exactly." For Huawei basic ACLs, always walk the rules in order and stop at the first hit; the action on that matched rule (not a later one) is what matters.

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