CCNA – IPv6
Note: If you are not sure about IPv6, please read our IPv6 tutorial.
Answer B is not correct because it has a letter “G”.
Answer C is not correct because it has a letter “H”.
Answer D is not correct because it has two “::”.
Anycast IPv6 addresses are 128-bit identifiers for interfaces and sets of interfaces. A packet sent to an anycast address is delivered to one of the interfaces identified by that address (the “nearest” one, according to the routing protocols’ measure of distance)
The range of IPv6 link-local address (similar to the Windows auto-configuration IP address of 169.254.x.x.) is FE80::/10. For more information about IPv6, please read my IPv6 tutorial.
An example of configuring RIPng (similar to RIPv2 but is used for IPv6) is shown below:
Router(config)#ipv6 unicast-routing (Enables the forwarding of IPv6 unicast datagrams globally on the router)
Router(config-if)#ipv6 rip 9tut enable (9tut is the process name of this RIPng)
Below is the list of common kinds of IPv6 addresses:
From the above table, we learn that A and D are correct while B and C are incorrect. Notice that the IPv6 unicast loopback address is equivalent to the IPv4 loopback address, 127.0.0.1. The IPv6 loopback address is 0:0:0:0:0:0:0:1, or ::1.
E is not correct because of anycast addresses which are indistinguishable from normal unicast addresses. You can think of anycast addresses like this: “send it to nearest one which have this address”. An anycast address can be assigned to many interfaces and the first interface receives the packet destined for this anycast address will proceed the packet. A benefit of anycast addressing is the capability to share load to multiple hosts. An example of this benefit is if you are a Television provider with multiple servers and you want your users to use the nearest server to them then you can use anycast addressing for your servers. When the user initiates a connection to the anycast address, the packet will be routed to the nearest server (the user does not have to specify which server they want to use).