Refer to the exhibit. Routers R1 and R2 are IPv6 BGP peers that have been configured to support a neighbor relationship over an IPv4 internetwork. Which three neighbor IP addresses are valid choices to use in the highlighted section of the exhibit? (Choose three.)
Correct Answer: ACE
Explanation/Reference:
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])
https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/interface/configuration/15-sy/ir-15-sy-book/ip6-auto-comp-tun.html
notice that the response A references the hexadecimal writing of the IPv4 address of 10.67.0.2
0A43:0002
0A is 10.
43 is .67: 3+4*16=67
0002 is .2