Chapter 7 - IP Addressing Flashcards
Remember the Class A range. The IP range for a Class A network is 1 through 126. This provides 8 bits of network addressing and 24 bits of host addressing by default.
Remember the Class B range. The IP range for a Class B network is 128 through 191. Class B addressing provides 16 bits of network addressing and 16 bits of host addressing by default.
Remember the Class C range. The IP range for a Class C network is 192 through 223. Class C addressing provides 24 bits of network addressing and 8 bits of host addressing by default.
Remember the private IP ranges.
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.
The Class C private address range is 192.168.0.0 through 192.168.255.255.
Remember the APIPA range. The IP address range for APIPA is 169.254.0.1 through 169.254.255.254. The client also configures itself with a default Class B subnet mask of 255.255.0.0.
Understand why we need IPv6. Without IPv6, the world would soon be depleted of IP addresses.
Understand link-local. Link-local addresses are like an IPv4 APIPA IP address, but it can’t be routed at all, not even in your organization.
Understand unique local.
This, like link-local, is like a private IP address in IPv4 and cannot be routed to the Internet. However, the difference between link-local and unique local is that unique local can be routed within your organization or company.
Remember IPv6 addressing. IPv6 addressing is not like IPv4 addressing. IPv6 addressing has much more address space and the address is 128 bits long, represented in hexadecimal, unlike an IPv4 address, which is only 32 bits long and represented in decimal.
Understand and be able to read a EUI-64 address with the 7th bit inverted.
Hosts can use autoconfiguration to obtain an IPv6 address, and one of the ways is through what is called EUI-64. This takes the unique MAC address of a host and inserts FF:FE in the middle of the address to change a 48-bit MAC address to a 64-bit interface ID. In addition to the 16 bits being inserted into the interface ID, the 7th bit of the first byte is inverted, typically from a 0 to a 1. Practice this with Written Lab 7.3.
- 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
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.
- 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
. 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.
- 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.
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 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
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 B address?
A. 10.1.1.1
B. 126.1.1.1
C. 129.1.1.1
D. 192.168.1.1
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 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).
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 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
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.
- In a Class C IP address, how long is the network address?
A. 8 bits
B. 16 bits
C. 24 bits
D. 32 bits
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.
- 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.
A. Packets addressed to a unicast address are delivered to a single interface. For load balancing, multiple interfaces can use the same address.
- 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. 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.
