Chapter 7 review questions

B. An IPv6 address is 128 bits in size.

An IPv4 address uses 32 bits. How many bits is an IPv6 address? A. 64 B. 128 C. 192 D. 255

B. This can be a hard question if you don't remember to invert the 7th bit! Always look for the 7th bit when studying for the exam. The EUI-64 autoconfiguration inserts an FF:FE in the middle of the 48-bit MAC address to create a unique IPv6 address.

IPv6 unicast routing is running on the Corp router. Which of the following addresses would be used as the EUI-64 address? Corp#sh int f0/0 FastEthernet0/0 is up, line protocol is up Hardware is AmdFE, address is 000d.bd3b.0d80 (bia 000d.bd3b.0d80) [output cut] A. FF02::3c3d:0d:bdff:fe3b:0d80 B. FE80::3c3d:2d:bdff:fe3b:0d80 C. FE80::3c3d:0d:bdff:fe3b:0d80 D. FE80::3c3d:2d:ffbd:3bfe:0d80

C. A default Class C subnet mask is 255.255.255.0, which means that the first three octets, or first 24 bits, are the network number.

In a Class C IP address, how long is the network address? A. 8 bits B. 16 bits C. 24 bits D. 32 bits

B. APIPA uses the link-local private address range of 169.254.0.0 through 169.254.255.255 and a subnet mask of 255.255.0.0. APIPA addresses are used by DHCP clients that cannot contact a DHCP server and have no static alternate configuration. These addresses are not Internet routable and cannot, by default, be used across routers on an internetwork.

A host automatically configured with an address from which of the following ranges indicates an inability to contact a DHCP server? A. 169.254.0.x with a mask of 255.255.255.0 B. 169.254.x.x with a mask of 255.255.0.0 C. 169.254.x.x with a mask of 255.255.255.0 D. 169.255.x.x with a mask of 255.255.0.0

C. I wonder how many of you picked APIPA address as your answer? An APIPA address is 169.254.x.x. The host address in this question is a public address. Somewhat of a tricky question if you did not read carefully.

A host is rebooted and you view the IP address that it was assigned. The address is 169.123.13.34. Which of the following happened? A. The host received an APIPA address. B. The host received a multicast address. C. The host received a public address. D. The host received a private address.

C, D. IPv4 addresses are 32 bits long and are represented in decimal format. IPv6 addresses are 128 bits long and represented in hexadecimal format.

What two statements about IPv4 and IPv6 addresses are true? (Choose two.) A. An IPv6 address is 32 bits long, represented in hexadecimal. B. An IPv6 address is 128 bits long, represented in decimal. C. An IPv4 address is 32 bits long, represented in decimal. D. An IPv6 address is 128 bits long, represented in hexadecimal.

B, D. In order to shorten the written length of an IPv6 address, successive fields of zeros may be replaced by double colons. In trying to shorten the address further, leading zeros may also be removed. Just as with IPv4, a single device's interface can have more than one address; with IPv6 there are more types of addresses and the same rule applies. There can be link-local, global unicast, and multicast addresses all assigned to the same interface.

What two statements about IPv6 addresses are true? (Choose two.) A. Leading zeros are required. B. Two colons (::) are used to represent successive hexadecimal fields of zeros. C. Two colons (::) are used to separate fields. D. A single interface will have multiple IPv6 addresses of different types.

D. The addresses in the range 172.16.0.0 through 172.31.255.255 are all considered private, based on RFC 1918. Use of these addresses on the Internet is prohibited so that they can be used simultaneously in different administrative domains without concern for conflict. Some experts in the industry believe these addresses are not routable, which is not true.

Which of the following addresses is not allowed on the Internet? A. 191.192.168.1 B. 191.168.169.254 C. 172.32.255.0 D. 172.31.12.251

. C, E. The Class A private address range is 10.0.0.0 through 10.255.255.255. The Class B private address range is 172.16.0.0 through 172.31.255.255, and the Class C private address range is 192.168.0.0 through 192.168.255.255.

Which of the following are private IP addresses? (Choose two.) A. 12.0.0.1 B. 168.172.19.39 C. 172.20.14.36 D. 172.33.194.30 E. 192.168.24.43

B. If you turned on all host bits (all of the host bits are 1s), this would be a broadcast address for that network.

Which of the following describes a broadcast address? A. All network bits are on (1s). B. All host bits are on (1s). C. All network bits are off (0s). D. All host bits are off (0s).

D. Only option D is in the Class C range of 192 through 224. It might look wrong because there is a 255 in the address, but this is not wrong—you can have a 255 in a network address, just not in the first octet.

Which of the following is a Class C network address? A. 10.10.10.0 B. 127.0.0.1 C. 128.0.0.0 D. 192.255.254.0

B. A Layer 2 broadcast is also referred to as a MAC address broadcast, which is in hexadecimal and is FF.FF.FF.FF.FF.FF.

Which of the following is a Layer 2 broadcast? A. FF.FF.FF.EE.EE.EE B. FF.FF.FF.FF.FF.FF C. 255.255.255.255 D. 255.0.0.0

D. The Class A range is 1 through 126 in the first octet/byte, so only option D is a valid Class A address.

Which of the following is a valid Class A address? A. 191.10.0.1 B. 127.10.0.1 C. 128.10.0.1 D. 126.10.0.1

C. The Class B range is 128 through 191 in the first octet/byte. Only option C is a valid Class B address.

Which of the following is a valid Class B address? A. 10.1.1.1 B. 126.1.1.1 C. 129.1.1.1 D. 192.168.1.1

C. Option C is a multicast address and cannot be used to address hosts.

Which of the following is an invalid IP address for a host? A. 10.0.0.1 B. 128.0.0.1 C. 224.0.0.1 D. 172.0.0.1

B. Packets addressed to a multicast address are delivered to all interfaces identified by the multicast address, the same as in IPv4. A multicast address is also called a one-to-many address. You can tell multicast addresses in IPv6 because they always start with FF.

Which of the following is true when describing a multicast address? A. Packets addressed to a unicast address from a multicast address are delivered to a single interface. B. Packets are delivered to all interfaces identified by the address. This is also called a one-to-many address. C. It identifies multiple interfaces and is delivered to only one address. This address can also be called one-to-one-of-many. D. These addresses are meant for nonrouting purposes, but they are almost globally unique so it is unlikely they will have an address overlap.

A. Packets addressed to a unicast address are delivered to a single interface. For load balancing, multiple interfaces can use the same address.

Which of the following is true when describing a unicast address? A. Packets addressed to a unicast address are delivered to a single interface. B. These are your typical publicly routable addresses, just like regular publicly routable addresses in IPv4. C. These are like private addresses in IPv4 in that they are not meant to be routed. D. These addresses are meant for nonrouting purposes, but they are almost globally unique, so it is unlikely they will have an address overlap.

C. Anycast addresses identify multiple interfaces, which is the same as multicast; however, the big difference is that the anycast packet is delivered to only one address: the first one it finds defined in terms of routing distance. This address can also be called one-to-one-ofmany or one-to-nearest.

Which of the following is true when describing an anycast address? A. Packets addressed to a unicast address from an anycast address are delivered to a single interface. B. Packets are delivered to all interfaces identified by the address. This is also called a one-to-many address. C. This address identifies multiple interfaces, and the anycast packet is delivered to only one address: the closest one. This address can also be called one-to-nearest. D. These addresses are meant for nonrouting purposes, but they are almost globally unique so it is unlikely they will have an address overlap.

C. Private IP addresses are not routable over the Internet, as either source or destination addresses. Because of that fact, any entity that wishes to use such addresses internally can do so without causing conflicts with other entities and without asking permission of any registrar or service provider. Despite not being allowed on the Internet, private IP addresses are fully routable on private intranets.

Which statement regarding private IP addresses is most accurate? A. Private addresses cannot be used in intranets that require routing. B. Private addresses must be assigned by a registrar or ISP. C. A remote host across the Internet cannot ping your host if it has a private address. D. Private addresses can only be used by a single administrative domain.

A, C. The loopback address with IPv4 is 127.0.0.1. With IPv6, that address is ::1

You want to ping the loopback address of your local host. Which two addresses could you type? (Choose two.) A. ping 127.0.0.1 B. ping 0.0.0.0 C. ping ::1 D. trace 0.0.::1