1.
What does CIDR stand for?
Correct Answer
E. Classless Interdomain Routing
Explanation
CIDR stands for Classless Interdomain Routing. CIDR is a method used to allocate and manage IP addresses more efficiently. It allows for the aggregation of multiple IP addresses into a single routing prefix, reducing the size of routing tables and improving the scalability of the internet. Unlike classful IP addressing, which divides IP addresses into fixed classes, CIDR allows for more flexible allocation of IP addresses, making it more suitable for the modern internet.
2.
Which of the following summarized subnets represent routes that could have been created for CIDR’s goal to reduce the size of Internet routing tables?
Correct Answer
D. 200.1.0.0 255.255.0.0
Explanation
CIDR’s original intent was to allow the summarization of multiple Class A, B, and C networks to reduce the size of Internet routing tables. Of the answers, only 200.1.0.0
255.255.0.0 summarizes multiple networks.
3.
Which of the following are not private addresses according to RFC 1918?
Correct Answer(s)
B. 172.33.1.1
E. 191.168.1.1
Explanation
RFC 1918 identifies private network numbers. It includes Class A network 10.0.0.0, Class B networks 172.16.0.0 through 172.31.0.0, and Class C networks 192.168.0.0 through 192.168.255.0.
4.
With static NAT, performing translation for inside addresses only, what causes NAT table entries to be created?
Correct Answer
C. Configuration using the ip nat inside source command
Explanation
With static NAT, the entries are statically configured. Because the question mentions translation for inside addresses, the inside keyword is needed in the command.
5.
With dynamic NAT, performing translation for inside addresses only, what causes NAT table entries to be created?
Correct Answer
A. The first packet from the inside network to the outside network
Explanation
With dynamic NAT, the entries are created as a result of the first packet flow from the inside network.
6.
NAT has been configured to translate source addresses of packets received from the inside part of the network, but only for some hosts. Which of the following commands identifies the hosts?
Correct Answer
A. Ip nat inside source list 1 pool barney
Explanation
The list 1 parameter references an IP ACL, which matches packets, identifying the inside local addresses.
7.
NAT has been configured to translate source addresses of packets received from the inside part of the network, but only for some hosts. Which of the following commands identifies the outside local IP addresses that are translated?
Correct Answer
E. None of the other answers are correct
Explanation
When translating inside addresses, the outside address is not translated, so the outside local address does not need to be identified in the configuration.
8.
Examine the following configuration commands:If the configuration is intended to enable source NAT overload, which of the following commands could be useful to complete the configuration?
Correct Answer(s)
A. The ip nat outside command
C. The overload keyword
Explanation
The configuration is missing the overload keyword in the ip nat inside source command and in the ip nat outside interface subcommand on the serial interface.
9.
Examine the following show command output on a router configured for dynamic NAT:Users are complaining about not being able to reach the Internet. Which of the following is the most likely cause?
Correct Answer
B. The NAT pool does not have enough entries to satisfy all requests.
Explanation
The last line mentions that the pool has seven addresses, with all seven allocated, with the misses counter close to 1000—meaning that close to 1000 new flows were rejected because of insufficient space in the NAT pool.
10.
Which of the following is the most likely organization from which an enterprise could obtain an administrative assignment of a block of IPv6 global unicast IP addresses?
Correct Answer
A. An ISP
Explanation
One method for IPv6 global unicast address assignment is that ICANN allocates large address blocks to RIRs, RIRs assign smaller address blocks to ISPs, and ISPs assign even smaller address blocks to their customers.
11.
Which of the following is the shortest valid abbreviation for FE80:0000:0000:0100:0000:0000:0000:0123?
Correct Answer
D. FE80:0:0:100::123
Explanation
Inside a quartet, any leading 0s can be omitted, and one sequence of 1 or more quartets of all 0s can be replaced with double colons (::). The correct answer replaces the longer 3-quartet sequence of 0s with ::.
12.
Which of the following answers lists a multicast IPv6 address?
Correct Answer
D. FF80::1:1234:5678:9ABC
Explanation
Global unicast addresses begin with 2000::/3, meaning that the first 3 bits match the value in hex 2000. Similarly, unique local addresses match FD00::/8, and link local
addresses match FE80::/10 (values that begin with FE8, FE9, FEA, and FED hex). Multicast IPv6 addresses begin with FF00::/8, meaning that the first 2 hex digits are F.
13.
Which of the following answers list either a protocol or function that can be used by a host to dynamically learn its own IPv6 address?
Correct Answer(s)
A. Stateful DHCP
C. Stateless autoconfiguration
Explanation
IPv6 supports stateful DHCP, which works similarly to IPv4’s DHCP protocol to dynamically assign the entire IP address. Stateless autoconfiguration also allows the assignment by finding the prefix from some nearby router and calculating the interface ID using the EUI-64 format.
14.
Which of the following help allow an IPv6 host to learn the IP address of a default gateway on its subnet?
Correct Answer(s)
A. Stateful DHCP
D. Neighbor Discovery Protocol
Explanation
Stateless autoconfiguration only helps a host learn and form its own IP address, but it does not help the host learn a default gateway. Stateless RS is not a valid term or feature. Neighbor Discovery Protocol (NDP) is used for several purposes, including the same purpose as ARP in IPv4, and for learning configuration parameters like a default gateway IP address.
15.
Which of the following are routing protocols that support IPv6?
Correct Answer(s)
A. RIPng
D. OSPFv3
Explanation
OSPFv3, RIPng, EIGRP for IPv6, and MP-BGP4 all support IPv6.
16.
In the following configuration, this router’s Fa0/0 interface has a MAC address of 4444.4444.4444. Which of the following IPv6 addresses will the interface use?
Correct Answer(s)
C. 3456::1
D. FE80::6444:44FF:FE44:4444
Explanation
The configuration explicitly assigns the 3456::1 IP address. The interface also forms the EUI-64 interface ID (6444:44FF:FE44:4444), adding it to FE80::/64, to form the link local IP address.
17.
In the configuration text in the previous question, RIP was not working on interface Fa0/0. Which of the following configuration commands would enable RIP on Fa0/0?
Correct Answer
E. Ipv6 rip tag1 enable
Explanation
RIPng configuration does not use a network command; instead, the ipv6 rip command is configured on the interface, listing the same tag as on the ipv6 router rip command, and the enable keyword.
18.
Which of the following IPv4-to-IPv6 transition methods allows an IPv4-only host to communicate with an IPv6-only host?
Correct Answer
D. NAT-PT
Explanation
Network Address Translation–Protocol Translation (NAT-PT) translates between IPv4 and IPv6, and vice versa. The two tunneling methods allow IPv6 hosts to communicate with other IPv6 hosts, sending the packets through an IPv4 network. Dual-stack allows a host or router to concurrently support both protocols.