CH8 - IPv4 Design - Q&A

List the RFC 1918 private address ranges.

10/8, 172.16/12 (172.16.0.0 to 172.31.255.255), and 192.168/16.

Which devices should be assigned an IP address dynamically? (Select three.) a. Cisco IP phones b. LAN switches c. Workstations d. Mobile devices e. Routers

A, C, and D. End-user workstations, Cisco IP phones, and mobile devices should have their IP addresses assigned dynamically.

Which of the following is true about fragmentation? a. Routers between source and destination hosts can fragment IPv4 packets. b. Only the first router in the network can fragment IPv4 packets. c. IPv4 packets cannot be fragmented. d. IPv4 packets are fragmented and reassembled at each link through the network.

A. IPv4 packets can be fragmented by the sending host and routers.

How many IP addresses are available for hosts in the subnet 198.10.100.64/27? a. 14 b. 30 c. 62 d. 126

B

What type of address is 225.10.1.1? a. Unicast b. Multicast c. Broadcast d. Anycast

B

Which of the following addresses is an IPv4 private address? a. 198.176.1.1 b. 172.31.16.1 c. 191.168.1.1 d. 224.130.1.1

B

What are three types of IPv4 addresses? a. Anycast b. Multicast c. Dynamic d. Broadcast e. Unicast f. Global g. Static

B, D, and E. The three types of IPv4 address are unicast, broadcast, and multicast.

Which of the following is a dotted-decimal representation of a /26 prefix mask? a. 255.255.255.128 b. 255.255.255.192 c. 255.255.255.224 d. 255.255.255.252

B. A /26 mask has 26 network bits and 6 host bits.

Which AF class is backward compatible with IP precedence bits' flash traffic? a. AF2 b. AF3 c. AF4 d. EF

B. AF3 is backward compatible with IP precedence priority traffic with a binary of 011.

What is the smallest subnet and mask that can be used in a DMZ network that needs to have only three hosts? a. 192.168.10.32/30 b. 192.168.10.32/29 c. 192.168.10.32/28 d. 192.168.10.32/27

B. Answer B allows up to six hosts. Answer A allows only two hosts, which is too small. Answer C allows 14 hosts, which is larger than Answer B.

Which protocol can you use to configure a default gateway setting on a host? a. ARP b. DHCP c. DNS d. RARP

B. DHCP configures the IP address, subnet mask, default gateway, and other optional parameters.

Which name resolution method reduces administrative overhead? a. Static name resolution b. Dynamic name resolution c. DHCP name resolution d. Host.txt name resolution

B. Dynamic name resolution reduces administrative overhead. Name-to-IP-address tables do not need to be configured.

A packet sent to a multicast address reaches what destinations? a. The nearest destination in a set of hosts. b. All destinations in a set of hosts. c. Broadcasts to all hosts. d. Reserved global destinations.

B. Multicast addresses are received by a set of hosts subscribed to the multicast group.

How many hosts can be addressed with the following IPv4 subnet: 172.30.192.240/28? a. 6 b. 14 c. 126 d. 1024

B. There are 4 bits to determine the number of host addresses: 24−2 = 16 − 2 = 14.

A company needs to use public IP addresses so that four network servers are accessible from the Internet. What technology is used to meet this requirement? a. DNS b. IPsec c. Static NAT d. Dynamic NAT

C

In what IPv4 field are the precedence bits located? a. Priority field b. IP Protocol field c. Type of Service field d. IP Options field

C

The DS field of DSCP is capable of how many codepoints? a. 8 b. 32 c. 64 d. 128

C

What protocol is used to automatically assign IP addresses? a. Dynamic Host Control Protocol b. Dedicated Host Configuration Protocol c. Dynamic Host Configuration Protocol d. Automatic Host Configuration Protocol

C

How many host addresses are available with a Class B network with the default mask? a. 63,998 b. 64,000 c. 65,534 d. 65,536

C. Class B networks have 16 bits for host addresses with the default mask: 216 − 2 = 65,534.

Which network and mask summarize the best smallest summary route? a. 192.170.20.0/24 b. 192.170.20.20/28 c. 192.170.20.16/29 d. 192.170.20.0/30

C. Network 192.170.20.16 with a prefix of /29 summarizes addresses from 192.170.20.16 to 192.170.20.23.

Which regional registry allocates address blocks in North America? a. IANA b. RIPE c. ARIN d. APNIC e. LACNIC d. AFRINIC

C. The American Registry for Internet Numbers allocates IP address blocks in for the United States, Canada, several parts of the Caribbean region, and Antarctica.

What subnet mask should you use in loopback addresses? a. 255.255.255.252 b. 255.255.255.254 c. 255.255.255.0 d. 255.255.255.255

D

What type of network and subnet mask would you use to save address space in a point-to-point WAN link? a. 100.100.10.16/26 b. 100.100.10.16/28 c. 100.100.10.16/29 d. 100.100.10.16/30

D

Which subnetworks are summarized by the following summary route: 150.10.192.0/21? a. 150.10.192.0/24, 150.10.193.0/24 b. 150.10.192.0/22, 150.10.196.0/23, 150.10.197.0/24 c. 150.10.192.0/22, 150.10.199.0/22 d. 150.10.192.0/23, 150.10.194.0/23, 150.10.196.0/23, 150.10.199.0/24, 150.10.198.0/24

D

Which modules cannot use private IPv4 address space? (Select all that apply.) a. Access b. Distribution c. Core d. E-commerce e. LAN f. WAN g. Internet Connection h. Data Center i. Remote Access/VPN

D G I

Which regional registry allocates address blocks in China? a. IANA b. RIPE c. ARIN d. APNIC e. LACNIC d. AFRINIC

D. The Asia-Pacific Network Information Centre allocates IP address blocks for Asia, Australia, New Zealand, and neighboring counties.

The IP header's ToS field is redefined as the DS field. How many bits does DSCP use for packet classification, and how many levels of classification are possible?

DSCP uses 6 bits, which provides 64 levels of classification.

True or false: 255.255.255.248 and /28 are two representations of the same IP mask.

False. The bit-number representation of 255.255.255.248 is /29. /28 is the same mask as 255.255.255.240.

True or false: The IP header's header checksum field performs the checksum of the IP header and data.

False. The header checksum field only includes a checksum of the IP header; it does not check the data portion.

Which technology allows a company to use a single public IP address when using private IPv4 addresses in the internal LAN? a. NAT b. Redistribution c. PAT d. access list

PAT

Which of the following is the European RIR? a. IANA b. ARIN c. RIPE d. ERIR

RIPE

When packets are fragmented at the network layer, where are the fragments reassembled?

The IP layer in the destination host.

Calculate the subnet, the address range within the subnet, and the subnet broadcast of the address 172.56.5.245/22.

The subnet is 172.56.4.0/22, the address range is from 172.56.4.1 to 172.56.7.254, and the subnet broadcast is 172.56.7.255.

True or false: NAT uses different IP addresses for translations. PAT uses different port numbers to identify translations.

True

True or false: Upper-layer protocols are identified in the IP header's protocol field. TCP is protocol 6, and UDP is protocol 17.

True

True or false: You can use DHCP to specify the TFTP host's IP address to a client PC.

True. You can use DHCP to specify several host IP configuration parameters, including IP address, mask, default gateway, DNS servers, and TFTP server.

Which technology allows you to divide address blocks into subnets of different sizes? a. NAT b. VLSM c. PAT d. Variable division subnet masks

VLSM

Fill in the blank: Without any options, the IP header is _________ bytes in length.

20