IPv6 Questions 3

Question 1

Explanation

We need to summarize three IPv6 prefixes with /64 subnet mask so the summarized route should have a smaller subnet mask. As we can see all four answers have the same summarized route of 2001:DB8:: so /48 is the best choice.

Note: IPv6 consists of 8 fields with each 16 bits (8×16 = 128). All the above prefix starts with 2001:DB8:0 (16 bits x 3 = 48) so we need at least /48 mask to summarize them.

Question 2

Question 3

Question 4

Explanation

DHCPv6 can be implemented in two ways : Rapid-Commit and Normal Commit mode. In Rapid-Commit mode , the DHCP client obtain configuration parameters from the server through a rapid two message exchange (solicit and reply).

The “solicit” message is sent out by the DHCP Client to verify that there is a DHCP Server available to handle its requests.

The “reply” message is sent out by the DHCP Server to the DHCP Client, and it contains the “configurable information” that the DHCP Client requested.

Just for your information, in Normal-Commit mode, the DHCP client uses four message exchanges (solicit, advertise, request and reply). By default normal-commit is used.

Question 5

Explanation

The IPv6-to-IPv6 Network Prefix Translation (NPTv6) provides a mechanism to translate an inside IPv6 source address prefix to outside IPv6 source address prefix in IPv6 packet header and vice-versa. In other words, NPTv6 is simply rewriting IPv6 prefixes. NPTv6 does not allow to overload. It does not support mismatching prefix allocations sizes (so the network/host portion remains intact. For example you cannot cover /64 to /48).

Question 6

Question 7

Question 8

Question 9

Explanation

The automatic tunneling mechanism uses a special type of IPv6 address, termed an “IPv4-compatible” address. An IPv4-compatible address is identified by an all-zeros 96-bit prefix, and holds an IPv4 address in the low-order 32-bits. IPv4-compatible addresses are structured as follows:

Therefore, an IPv4 address of 10.67.0.2 will be written as ::10.67.0.2 or 0:0:0:0:0:0:10.67.0.2 or ::0A43:0002 (with 10[decimal] = 0A[hexa] ; 67[decimal] = 43[hexa] ; 0[hexa] = 0[decimal] ; 2[hexa] = 2[decimal])

Question 10