When a large enterprise deploys WLAN layer 3 networking, it is necessary to configure the Option 43 field on the Windows 2003 DHCP Server to notify the AP of the AC's IP address. The IP address of…

Question

Options

• A030831302E32332E3130302E31
• B040831302E32332E3130302E31
• C030B31302E32332E3130302E31
• D030B31302E32332E31302E3031

• A
  4% (2)
• B
  9% (4)
• C
  85% (40)
• D
  2% (1)

Explanation

Option 43 for Huawei WLAN uses a TLV (Type-Length-Value) structure: the first byte is the sub-option type (03 for AC IP), the second byte is the ASCII character count of the IP string, and the remaining bytes are the ASCII hex encoding of the IP address. The string "10.23.100.1" is 11 characters long, which is 0B in hex, making 03 0B 31302E32332E3130302E31 the only fully correct encoding - that's option C.

• A fails because the length byte is 08 (8), not 0B (11) - the IP string is 11 characters, not 8.
• B fails on two counts: the type byte is 04 instead of 03, and the length is also wrong (08).
• D has the correct type (03) and length (0B), but decoding the value bytes gives 10.23.10.01 - the digits of 100 are scrambled - not the target IP 10.23.100.1.

Memory tip: Think "Count the dots and digits" - before checking anything else, manually count the characters in the IP address string (including the dots), convert that count to hex, and verify it matches the second byte; this quickly eliminates distractor answers that only alter the length or slightly rearrange the IP digits.

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