Exam 200-301 topic 1 question 912 discussion

/128(for IPv6) is the equivalent to /32(for IPv4). Both are host subnets.

i would go with D

In IPv6, a /128 prefix length is used for an individual address, such as a loopback address, which is a single host address. The IPv6 address 0:0:0:0:0:ffff:a36:4901 (or ::ffff:10.54.73.1 in the compressed form) is an IPv4-mapped IPv6 address. This type of address maps an IPv4 address into the IPv6 address space. For a loopback interface, which represents a single, specific address, /128 is the most appropriate prefix length.

it´s D

Ya'll who gone and done select B are getting yourselves confused. Yes I'm talking to you Junior_Network and Rick3390. ::ffff:0:0/96 is simply the CIDR address block for IPv4 mapped addresses. The /96 prefix length is used because the remaining 32 bits (128-96) are used for the 32 bits needed in IPv4. So in this instance we take the IPv4 address - 10.54.73.1 - and format each octet as hex. We get 0A.36.49.01. We then format this as two consecutive octets, getting 0A36:4901. We finally append the IPv6 address block for IPv4 mapped addresses and get a new IPv6 host address: ::ffff:0:0:A36:4901/128 The prefix length is 128, because all 128 bits are fixed. Nothing works different about that here.

Correct answer is B.

I think B is correct answer. ::ffff:0:0/96 — This prefix is used for IPv6 transition mechanisms and designated as an IPv4-mapped IPv6 address. From https://en.wikipedia.org/wiki/IPv6_address

D is wrong, because the ipv6 address the question mention is clearly the same ipv4 mapped in the new ipv6, therefore, the mask will be /96. When an IPv4 address is mapped into an IPv6 address, the standard notation uses a /96 prefix. This is because the first 96 bits are used for the fixed prefix (0:0:0:0:0:ffff:), and the remaining 32 bits are used for the mapped IPv4 address. So, for an IPv4-mapped address, a /96 is used to indicate that this is an IPv4 address mapped into the IPv6 space. The IPv4 address 10.54.73.1 is represented in hexadecimal as a36:4901, all we need is a little math to figure it out.

D. /128 /128 (Ipv6) is the equivalent to /32 for IPv4

D is correct an /32 Ipv4 subnet mask is an /128 Ipv6 subnet mask

Correct answer is D, half these answers are incorrect 😂

It should be D. The equivalent subnet mask in IPv6 for an IPv4 /32 subnet mask is /128 and here're sample loopback interface config steps: configure terminal interface loopback 0 ipv6 address 2001:db8::1/128 no shutdown exit show interface loopback 0

I think loopback interfaces are configured at /32 for IPv4 and /128 for IPv6.

D boys

The correct answers is D