Chapter 5 and 6

Which of the following are distance-vector routing protocol features that can prevent routing loops? (Choose two.) a. Reverse path forwarding (RPF) check b. Split horizon c. Poison reverse d. Rendezvous point

b, c. Split horizon and poison reverse are critical loop preventions for early routing protocols.

What NAT variation automatically assigns an inside global address from a pool of available addresses? a. SNAT b. DNAT c. PAT d. GNAT

b. Dynamic NAT permits dynamic mappings.

What technology allows for the automatic assignment of the host portion of an IPv6 address? a. Dual Stack b. EUI64 c. Neighbor discovery d. Anycast

b. EUI64 in IPv6 permits the automatic generation of host portions of addresses.

Which of the following are dynamic approaches to assigning routable IP addresses to networked devices? (Choose two.) a. BOOTP b. APIPA c. Zeroconf d. DHCP

a, d. Notice that a key to this question is "routable IP addresses." Only BOOTP and DHCP are valid options in this case.

Which of the following routing protocols is an EGP? a. BGP b. IS-IS c. RIP d. OSPF

a. BGP is the protocol that makes the Internet a reality.

What is the class of IP address 10.1.2.3/24? a. Class A b. Class B c. Class C d. Class D

a. Because the decimal value 10 appears in the first octet, we know that this is a Class A address.

What multicast protocol is used between clients and routers to let routers know which of their interfaces are connected to a multicast receiver? a. IGMP b. PIM-DM c. PIM-SM d. SPT switchover

a. The client-to-router protocol in multicast is IGMP.

How many assignable IP addresses exist in the 172.16.1.10/27 network? a. 30 b. 32 c. 14 d. 64

a. There are 5 bits left here for host address assignment, and 2 raised to the fifth power is 32. You then subtract 2 for the network ID and broadcast address.

A client with an IP address of 172.16.18.5/18 belongs to what network? a. 172.16.0.0/18 b. 172.16.64.0/18 c. 172.16.96.0/18 d. 172.16.128.0/18

a. This host address and subnet mask combination references the following subnet of usable addresses: 172.16.0.1 to 172.16.63.254.

If a PC on an Ethernet network attempts to communicate with a host on a different subnet, what destination IP address and destination MAC address will be placed in the packet/frame header sent by the PC? a. Dest. IP: IP address of default gateway. Dest. MAC: MAC address of default gateway. b. Dest. IP: IP address of remote host. Dest. MAC: MAC address of default gateway. c. Dest. IP: IP address of remote host. Dest. MAC: MAC address of remote host. d. Dest. IP: IP address of remote host. Dest. MAC: MAC address of local PC.

b. Note that the destination IP address does not change in the packet. However, as the router sends the frame out the exit interface heading toward the destination, it will update the destination MAC address to the next hop/device.

What is the binary representation of the decimal number 117? a. 10110101 b. 01110101 c. 10110110 d. 01101001

b. The binary representation of 117 is 01110101. Notice that this has values of 64 + 32 + 16 + 4 + 1.

What NAT IP address is a public IP address that maps to an inside device? a. Inside local b. Inside global c. Outside local d. Outside global

b. The inside global address permits devices on the outside to reach devices on the inside.

What is the prefix notation for a subnet mask of 255.255.255.240? a. /20 b. /24 c. /28 d. /29

c. /28 is the prefix notation for 255.255.255.240. Notice the mask consists of 8 bits + 8 bits + 8 bits + 4 bits.

Which of the following is a distance-vector routing protocol with a maximum usable hop count of 15? a. BGP b. IS-IS c. RIP d. OSPF

c. RIP cannot be used in large networks due to a maximum hop count of 15.

How can the following IPv6 address be condensed? 2009:0123:4040:0000:0000:000:000A:100B a. 2009::123:404:A:100B b. 2009::123:404:A:1B c. 2009:123:4040::A:100B d. 2009:0123:4040::0::000A:100B

c. Remember, you can drop the leading zeros in any field, and once within an address you can represent continuous sections of zeros with the shorthand symbol of ::.

What routing protocol characteristic indicates the believability of the routing protocol (as opposed to other routing protocols)? a. Weight b. Metric c. Administrative distance d. SPF algorithm

c. The better the administrative distance, the more believable the protocol. Lower is better for the AD score.

Your company has been assigned the 192.168.30.0/24 network for use at one of its sites. You need to use a subnet mask that will accommodate seven subnets while simultaneously accommodating the maximum number of hosts per subnet. What subnet mask should you use? a. /24 b. /26 c. /27 d. /28

c. Using a /27 mask gives you 3 bits for subnetting. This permits the creation of eight subnets and satisfies your requirement of seven and gives you the most possible host addresses per subnet.

The binary number 10110100 has what decimal equivalent? a. 114 b. 190 c. 172 d. 180

d. 10110100 is the equivalent of 180 because we have 128 + 32 + 16 + 4.

What type of IPv4 address is 239.1.2.3? a. Unicast b. Experimental c. Private use only d. Multicast

d. 239.1.2.3 is an example of a multicast IP address. We use multicast to send a single packet to groups of systems that have "subscribed" to this address.

What protocol is used to request a MAC address that corresponds to a known IPv4 address on the local network? a. IGMP b. TTL c. ICMP d. ARP

d. ARP is one of the many name resolution protocols we deal with. In this case, the names are Layer 2 and Layer 3 addresses.

What is the network address and subnet mask of a default route? a. 255.255.255.255/32 b. 0.0.0.0/32 c. 255.255.255.255/0 d. 0.0.0.0/0

d. The default route is 0.0.0.0/0.