Ch8: Network Configuration Concepts
A host is configured with the IP address 192.168.1.10/24. What is the host's subnet mask?
255.255.255.0.
What is the purpose of a DHCP server?
A Dynamic Host Configuration Protocol (DHCP) server automatically allocates aTCP/IP configuration (IP address, subnet mask, default gateway, and DNS servers) to hosts when they join the network.
What is meant by dotted decimal notation?
An IPv4 address is a 32-bit number expressed as four octets (bytes). A byte can be expressed as the decimal values 0 to 255, and these are used to represent the IP address, with dots between each decimal number. This scheme is easier for people to read than a binary number and reduces configuration errors.
What is the difference between a router and a modem?
A router is a device that can forward traffic between different logical networks. These networks might use different media and different ways of transporting frames across links. In an Ethernet network, a host interfaces with the local network (LAN) using a network adapter. When a link is point-to-point, using media such as a telephone line, a modem is used to convert the signals that can be carried over the media from the LAN format to the WAN format. Where a router is connected to such links, it may be installed with a modem, but the functions of the devices are separate. The modem makes a physical network link with the ISP network, functioning at the same level as a switch. The router can make decisions about forwarding between logical networks.
Apart from its length, what is the main difference between the structure of an IPv4 address and an IPv6 address?
Both types of IP address identify a host within a specific logical network. In an IPv4 address, the network ID portion is determined by applying a mask to the whole address. In an IPv6 address, the host portion is always the last 64 bits of the address. The first 64 bits are used with network prefixes to identify networks and subnetworks.
A host is configured with the IP address 172.29.0.101. What is significant about this address?
It is a private address and cannot be reached directly over the Internet. The host must use a router with address translation or a proxy service to communicate on the Internet.
What is special about an IP address that starts 169.254?
It is an APIPA address—that is, one automatically selected if the interface is configured to use DHCP but cannot contact a DHCP server.
Protocols within the TCP/IP suite (and products supporting TCP/IP networks) are conceived as working at one of four layers.What are those four layers called?
Link/Network Interface, Internet, Transport, and Application.
What is the function of NAT?
Network Address Translation (NAT) enables a router to map private network IP addresses onto a public IP address. Private addressing keeps the local network more secure and reduces the demand for unique IP addresses.
When is a default gateway required?
When a host needs to communicate with hosts located outside its own IP network.