1. A network design engineer has been asked to design the IP addressing scheme for a customer network. The network will use IP addresses from the 192.168.30.0/24 network. The engineer allocates 254 IP addresses for the hosts on the network but excludes 192.168.30.0/24 and 192.168.30.255/24 IP addresses. Why must the engineer exclude these two IP addresses?
- 192.168.30.0/24 is the IP address reserved for the default gateway, and 192.168.30.255/24 is the IP address reserved for the DHCP server.
- 192.168.30.0/24 is the network IP address and 192.168.30.255/24 is the IP broadcast address.
- 192.168.30.0/24 and 192.168.30.255/24 IP addresses are reserved for outside Internet connectivity.
- 192.168.30.0/24 and 192.168.30.255/24 IP addresses are reserved for the email and DNS servers.
Explanation: The IPv4 addressing system is a hierarchical addressing system. An IPv4 address is made up of two parts, the network address and the host address. When the host portion is all “0s” in binary, it is designated as a network address. When the host portion is all “1s” in binary, it is designated as a broadcast address. These two addresses cannot be assigned to individual hosts.
2. What are three private IPv4 address? (Choose three.)
- 224.6.6.6
- 172.32.5.2
- 192.168.5.5
- 10.1.1.1
- 172.16.4.4
- 192.167.10.10
Explanation: Private IP addresses are reserved to be exclusively used for internal networks and they cannot be used on the Internet. IPv4 addresses in the networks, 10.0.0.0/8, 172.16.0.0/16-172.31.0.0/16, and 192.168.0.0/24-192.168.255.0/24, are designated as private IPv4 addresses.
3. Which address prefix range is reserved for IPv4 multicast?
- 224.0.0.0 – 239.255.255.255
- 127.0.0.0 – 127.255.255.255
- 169.254.0.0 – 169.254.255.255
- 240.0.0.0 – 254.255.255.255
Explanation: Multicast IPv4 addresses use the reserved class D address range of 224.0.0.0 to 239.255.255.255.
4. Why does a Layer 3 device perform the ANDing process on a destination IP address and subnet mask?
- to identify the broadcast address of the destination network
- to identify the network address of the destination network
- to identify faulty frames
- to identify the host address of the destination host
Explanation: ANDing allows us to identify the network address from the IP address and the network mask.
5. What are three characteristics of a multicast transmission? (Choose three.)
- Computers use multicast transmission to request IPv4 addresses.
- The source address of a multicast transmission is in the range of 224.0.0.0 to 224.0.0.255.
- Routers will not forward multicast addresses in the range of 224.0.0.0 to 224.0.0.255.
- A single packet can be sent to a group of hosts.
- Multicast messages map lower layer addresses to upper layer addresses.
- Multicast transmissions can be used by routers to exchange routing information.
Explanation: Broadcast messages consist of single packets that are sent to all hosts on a network segment. These types of messages are used to request IPv4 addresses, and map upper layer addresses to lower layer addresses. A multicast transmission is a single packet sent to a group of hosts and is used by routing protocols, such as OSPF and RIPv2, to exchange routes. The address range 224.0.0.0 to 224.0.0.255 is reserved for link-local addresses to reach multicast groups on a local network.
6. When IPv4 is configured for a computer on a network, what does the subnet mask identify?
- the dynamic subnetwork configuration
- the device that the computer uses to access another network
- the part of the IP address that identifies the network
- the pool of addresses assigned within the network
Explanation: The IP addressing system is a hierarchical addressing system. An IP address is made up of two parts: the network address and the host address. For IPv4, the subnet mask is used to identify which portion of an IPv4 address is the network address and which portion is the host address.
7. Which network does a host with IP address 172.32.65.13 reside on if it is using a default subnet mask?
- 172.32.0.0
- 172.32.65.32
- 172.32.32.0
- 172.32.65.0
Explanation: In classful IPv4 addressing, a network with the first octet of 172 is a Class B network with the default subnet mask 255.255.0.0. Thus the network address is 172.32.0.0.
8. A technician is setting up equipment on a network. Which three devices will need IP addresses? (Choose three.)
- a server with two NICs
- a web camera that is attached directly to a host
- a printer with an integrated NIC
- a PDA that is attached to a networked workstation
- an IP phone
- a wireless mouse
Explanation: A device needs an IP address in order to connect to a network. A device that is attached to a networked device can use the established connection to access the network.
9. Which IP address type is intended for a specific host?
- multicast
- broadcast
- unicast
- simulcast
Explanation: A communication that has a single source going to a single destination is a unicast. A communication from a single source to a group of destinations is a multicast. A communication from a single source to all destinations on the same local network is a broadcast.
10. What is the equivalent decimal value given a binary number of 11001010?
- 212
- 202
- 240
- 196
Explanation: The equivalent decimal value for a binary number of 11001010 can be determined by 12^7+12^6+12^3+12^1.
11. How many usable hosts are available given a Class C IP address with the default subnet mask?
- 256
- 254
- 252
- 255
Explanation: The default subnet mask for a Class C network is 255.255.255.0. Thus there are 8 bits available for assigning host addresses. Eight bits in binary is equivalent to 256 in decimal (2^8 = 256). These numbers are from 0 to 255. However, host portion 0 is reserved for the network address, and the host address with all 1s (in this case 255) is reserved for the broadcast address. Therefore, usable host addresses are 256-2=254.
12. What are two differences between binary and decimal numbers? (Choose two.)
- Numbers typed on a keyboard are entered as binary and converted to decimal by the computer.
- Binary numbers are based on powers of 2.
- Decimal numbers are based on powers of 1.
- Decimal numbers include 0 through 9.
- Binary numbers consist of three states: on, off, null. Decimal numbers do not have states.
Explanation: Computing devices use the binary system for data processing and storage. Binary numbers are based on powers of 2 and decimal numbers are based on powers of 10.