For which two reasons was RFC 1918 address space define (Choose two)
A. to preserve public IPv4 address space
B. to reduce the occurrence of overlapping IP addresses
C. to preserve public IPv6 address space
D. reduce the size of ISP routing tables
E. to support the NAT protocol
you cant have overlapping public ip addresses… their assigned and even if you decide to use a self assigned public ip address the PE wont advertise the public addresses into BGP you self assigned
D is irrelevant… a /8 public or a /8 private ip addresses will use the same amount of memory
A+E is correct
RFC 1918 was used to create the standards by which networking equipment assigns IP addresses in a private network. A private network can use a single public IP address. So it’s meant to preserve IPv4 address space for private addressing and reduce overlapping of IP addresses (public and private). Not a really good / well worded question but those are the two that make any possible sense. D/E is wrong.
Correct answers : A + B