100-150 Question 83
Single answerYou are troubleshooting a network issue and come across the following IPv6 address: 2001:0db8:85a3:0000:0000:8a2e:0370:7334/64. What does the '/64' in the address signify?
- A
It represents the total number of bits in the address.
- B
It indicates the size of the subnet prefix.
- C
It specifies the portion of the address used for the host ID.
- D
It defines the type of IPv6 address being used.
Show answer and explanation
Correct answer: B
Explanation
In IPv6, the '/64' in an address represents the subnet prefix length, meaning the first 64 bits of the address are reserved for the network portion, while the remaining 64 bits are used for the host ID. Understanding prefix lengths is essential for configuring and troubleshooting IPv6 networks.
- A. Incorrect.
Incorrect. The IPv6 address is always 128 bits long, regardless of the prefix length.
- B. Correct.
Correct. The '/64' signifies that the first 64 bits of the address are used for the network (subnet) prefix.
- C. Incorrect.
Incorrect. While the remaining bits after the prefix length are used for the host ID, '/64' specifically refers to the subnet prefix length, not the host ID.
- D. Incorrect.
Incorrect. The '/64' does not define the type of IPv6 address; it only indicates the prefix length.