2.10 - Implement IP version 4 (IPv4) addressing, subnetting, and variable-length subnet masking (VLSM)

Question 1

What is the maximum possible size of an IP Packet?

Answer 1

65,535 octets

Question 2

What IP addresses are in the Class A range?

Answer 2

0.0.0.0 - 127.255.255.255

Question 3

What IP addresses are in the Class B range?

Answer 3

128.0.0.0 - 191.255.255.255

Question 4

What IP addresses are in the Class C range?

Answer 4

192.0.0.0 - 223.255.255.255

Question 5

How can you determine a Class A address in binary?

Answer 5

The left most bit of the entire 32-bit string is always 0

Question 6

How can you determine a Class B address in binary?

Answer 6

The left most bit of the entire 32-bit string is always 1 and the second bit is 0

Question 7

How can you determine a Class C address in binary?

Answer 7

The first 2 bits of the entire 32-bit string are set to 1 while the third bit is 0

Question 8

What IP addresses are defined by RFC 1918

Answer 8

10.0.0.0/8, 172.16.0.0/12 & 192.168.0.0/16

Question 9

How do you enable proxy ARP?

Answer 9

router(config-if)# ip proxy-arp

Question 10

How do you disable proxy ARP?

Answer 10

router(config-if)# no ip proxy-arp

Question 11

What is the default age of ARP entries on Cisco devices?

Answer 11

Four hours (14,400 seconds)

Question 12

What is the command to change the ARP timeout on a Cisco device?

Answer 12

router(config-if)# arp timeout

Question 13

What is the command to enter a static ARP entry on a cisco device?

Answer 13

router(config)# arp

Question 14

What is the command to clear the ARP cache on a Cisco device?

Answer 14

clear arp-cache

Question 15

Describe proxy ARP.

Answer 15

Sometimes called promiscuous ARP, it allows a router to pose as a device on a connected network and reply to devices that do not have default gateways set.

Question 16

Describe gratuitous ARP.

Answer 16

An ARP request sent with the senders IP address in the target address field.

Question 17

Describe IP redirects.

Answer 17

Used to tell hosts to use a different gateway to reach an IP address.

Question 18

What ICMP type is a redirect?

Answer 18

ICMP type 5

Question 19

How do you disable IP redirects?

Answer 19

router(config-if)# no ip redirects

Question 20

What fields in the IP header are used for fragmentation?

Answer 20

Flags and fragment offset

Question 21

What is TTL?

Answer 21

Time to Live

Question 22

How is TTL calculated?

Answer 22

Every router decrements the value by one, once value reaches 0 the packet is discarded.

Question 23

What command changes load sharing to be by destination on a cisco router?

Answer 23

router(config)#ip load-sharing per-destination

Question 24

What command changes load sharing to be by packet on a cisco router?

Answer 24

router(config)#ip load-sharing per-packet

Question 25

What is the command to determine the type of load sharing on an interface?

Answer 25

show cef interface

Question 26

What is the command to enable process switching on a cisco?

Answer 26

no ip route-cache