Chapter 2-How computers find each other on Networks Flashcards
Fully qualified host name
A host name plus domain name that uniquely identifies a computer or location on a network.
gateway
A computer, router, or other device that a host uses to access another network. Gateways perform connectivity, session management, and data translation, so they must operate at multiple layers of the OSI model.
global address
same at global unicast address
global unicast address
An IPv6 address that can be routed on the Internet. These addresses are similar to public IPv4 address. Most global address begin with the prefix 2000::/3, although other prefixes are being released.
H.323
A signaling protocol used to make a connection between host prior to communicating multimedia data. H.323 has largely been replaced by SIP, which is easier to use.
hex number
same as hexadecimal number
hexadecimal number
A number written in the base 16 numbering system, which uses the 16 numerals 0,1,2,3,4,5,6,7,8,9,A,B,C,D,E, and F
host name
The first part of an FGDN, such as www or ftp, which identifies the individual computer on the network
hosts file
A text file that associates TCP/IP host names with IP addresses. On a UNIX-or Linux-based computer, host is hound in the /etc directory. On a Windows-based computer, it is found in the %\system32\drivers\etc folder
ICMPv6
The version of ICMP used with IPv6 networks. ICMPv6 performs the functions that ICMP, IGMP, and ARP perform in IPv4. It detects and reports data transmission errors, discovers other nodes on a network, and manages multicasting.
ifconfig
A TCP/IP configuration and management utility used with UNIX and Linux systems.
interface
A network connection made by a node or host on a network.
interface ID
The last 64 bits, or four blocks, of an IPv6 address that uniquely identify the interface on the local link.
Internet Corporation for Assigned Names and Numbers (ICANN)
The nonprofit corporation currently designated by the U.S. government to maintain process and that packets were not delivered.
Internet Protocol version 4 (IPv4)
The internet protocol standard released in the 1980s and still commonly used on modern networks. It specifies 32-bit addresses composed of four octets.
Internet Protocol version 6 (IPv6)
A standard for IP addressing that is gradually replacing the current IPv4. Most notably, IPv6 uses a newer, more efficient header in its packets and allows for 128-bit souce and destination IP addresses, which are usually written as eight blocks of hexadecimal numbers, such as 2001:0DB8:0B80:0000:0000:00D3:9C5A:00CC
ipconfig
The utility used to display TCP/IP addressing and domain name information in the Windows client operating systems.
ISATAP (Intra-Site Automatic Tunnel Addressing Protocol)
A tunneling protocol that enables transmission of IPv6 packets over IPv4 networks. This protocol works only on a single orzanization’s intranet
iterative query
A DNS query that does not demand a resolution, which means the server provides the information only if it already has that information available.
link
Any local area network (LAN) bounded by routers.
link local address
An IP address that is automatically assigned by an operating system to allow a node to communicate over its local subnet if a routable IP address is not available. ICANN has established the range of 169.254.0.0 through 169.254.254.255 as potential link-local IPv4 addresses. IPv6 link-local addresses begin with the prefix FE80::/10
link local unicast address
An IPv6 address that can be used for communicating with nodes in the same link. These addresses are similar to IPv4’s autoconfigured APIPA addresses and begin with the prefix FE80::/10
local link
see link
loopback address
An IP address reserved for communicating from a node to itself, used mostly for troubleshooting purposes. The IPv4 loopback address is always cited as 127.0.0.1, and the IPv6 loopback address is ::1.
loopback interface
A computer’s connection with itself
MGCP (Media gateway control protocol)
A protocol used for communication between media gateway controllers and media gateway.
Miredo
A third-party software that provides Teredo service on UNIX and Linux systems
multicast address
A type of IPv6 address that represents multiple interfaces, often on multiple nodes. An IPv6 multicast address begins with the following hexadecimal field: FF0x, where x is a character that identifies the address’s group scope.
multicasting
A means of transmission in which one device sends data to a specific group of devices (not necessarily the entire network segment) in a point-to-multipoint fashion.
MX (Mail exchanger) record
A type of DNS data record that identifies a mail server and that is used for email traffic.
name resolution
The entire collection of Internet IP addresses and their associated names distributed over DNS name servers worldwide.
name server
Also a DNS server which is a hierarchical way of tracking domain names and their addresses, devised in the mid-1980s. The DNS database does not rely on one file or even one server, but rather is distributed over several key computers across the Internet to prevent catastrophic failure if one or a few computers fo down, DNS is a TCP/IP service that belongs to the Application layer of the OSI model.
namespace
The entire collection of Internet IP addresses and their associated names distributed over DNS name servers worldwide.
neighbor
Two or more nodes on the same link.
NetBIOS
A protocol that runs in the session and transport layers of the OSI model and associates NetBIOS names with workstations, NetBIOS allows old applications designed for out-of-date NetBIOS networks to work on TCP/IP networks
NetBT (NetBIOS over TCP/IP)
Also NetBIOS
Network address translation (NAT)
A technique in which IP addresses used on a private network are assigned a public IP address by gateway when accessing a public network.
octal number system
A system founded on using eight numbers (0 through 7) to encode information
octet
One of the 4 bytes that are separated by periods and together make up an IPv4 address.
open source
The term that describes software whose code is publicly available for use and modification.
OUI (Organizationally Unique Identifier)
A 24-bit character sequence assigned by IEEE that appears at the beginning of a network interface’s physical address and identifies the NIC’s manufacturer.
packet analyzer
Also called protocol analyzer.
ping (Packet Internet Groper)
A TCP/IP troubleshooting utility that can verify that TCP/IP is installed, bound to the NIC, configured correctly, and communication with the network. Ping uses ICMP to send echo request and echo reply messages that determine the validity of an IP address.
ping -6
The version of the ping utility used on Windows computers that run IPv6.
ping6
The version of the ping utility used on Linux computers that run IPv6.
Port address translation (PAT)
A form of address translation that assigns a separate TCP port number to each ongoing conversion, or session, between a local host and an Internet host.
private IP address
IP adresses that can be used on a private network but on the Internet. IEEE recommends the following IP address ranges for private use: 10.0.0.0 through 10.255.255.255; 172.16.0.0 through 172.31.255.255; and 192.168.0.0 through 192.168.255.255
private port
A port assigned by a network administrator that is different from the well-known port number normally used for that service.
protocol analyzer
A software package or hardware-based tool that can capture and analyze data on a network. Protocol analyzers are more sophisticated than network monitoring tools, as they can typically interpret data up to Layer 7 of the OSI model.
PTR (Pointer) record
A type of DNS data record that is used for reverse lookups, to provide a host name when the IP address is known
public IP address
An IP address that is valid for use on public networks, such as the Internet. An organization assigns its host public addresses from the range of addresses assigned to it by Internet numbering authorities.
recursive query
A DNS query that demands a resolution or the response that the information can’t be found.
registered port
The TCP/IP ports in the range of 1024 to 49,151. These ports can be used by network users and processes that are not considered standard processes. Default assignments of these ports must be registered with IANA.
reservation
A static IP address assigned by DHCP
resolver
A DNS client that request information from DNS name servers.
resource record
The element of A DNS database stored on a name server that contains information about TCP/IP host names and their addresses.
reverse DNS lookup
A function that finds the host name of a device whose IP address is known.
root server
A DNS server maintained by ICANN and IANA that is an authority on how to contact the top-level domains, such as those ending with .com, .edu, .net, .us, and so on. ICANN oversees the operation of 13 clusters of root servers around the world
Samba
An open source software package that provides complete Windows-style file- and print- sharing capabilities.
scope ID
A % sign and a number at the end of an IPv6 address that is used to identify the link the computer belongs to.
shell prompt
Another term for the UNIX command interpreter.
signaling protocol
A protocol that makes an initial connection between hosts but that does not actually participate in data exchange.
SIP (session initiation protocol)
A set of Application layer signaling and control protocols for multiservice, packet-based networks. SIP is used to make an initial connection between hosts for transferring multimedia data.
SMB (Server Message Block)
A protocol for comminications and resources access between systems, such as clients and servers. SMB was first used by earlier Windows OSs for file sharing on a network. UNIX uses a version of SMB in its Samba software. The cross-platform version of SMB used between Windows, UNIX, and other operating systems is called the CIFS (Common Internet File System) protocol.
SNMP (simple network management protocol)
A response from a managed device’s agent to the NMS providing requested information.
socket
A logical address consisting of a host’s IP address and the port number of an application running on the host with a colon separating the two values. For example, if a host has an IP address of 10.43.3.87, the socket address for Telnet running on that host is 10.43.3.87:23
split DNS
An implementation of DNS where internal and external DNS queries are handled by different DNS servers or by a single DNS server that is specially configured to keep internal and external DNS zones separate.
split-horizon DNS
A method for preventing routing loops. This layer 3 technology is employed by distance-vector routing protocols to ensure that a router knows which of its interfaces received a routing update so the router will not transmit that same update back on the same interface.
static IP address
An IP address that is manually assigned to a device and remains constant until it is manually changed.
Static network address translation (SNAT)
A type of address translation in which a gateway assigns the same public IP address to a host each time it makes a request to access the Internet.
subnet
A smaller network within a larger network in which all nodes share a network addressing component and a fixed amount of bandwidth.
subnet ID
The 16 bits, or one block, in an IPv6 address that can be used to identify a subnet on a large corporate network.
subnet mask
In IPv4 addressing, a 32-bit number that helps one computer find another by indicating what portion of an IP address is the network portion and what portion is the host portion.
Teredo
A tunneling protocol, named after the Teredo worm, that enables transmission of IPv6 packets over IPv4 networks. IPv6 addresses intended to be used by this protocol begin with the prefix 2001::/32
TFTP (Trivial file transfer protocol)
A TCP/IP Application layer protocol that is seldom used by humans. Computers commonly use it as they are cooting up to request configuration files from another computer on th elocal network. Unlike FTP, TFTP relies on UDP at the Transport layer using port 69.
time to live field
A field in a DNS resource record that identifies how long the record should be saved in a cache on a server. This field is included in zone transfers.
top-level domain (TLD)
The last part of an FQDN and the highest-level category used to distinguish domain names-for example, .org, .com, and .net. A TLD is also known as the domain suffix.
tunneling
The process of encapsulating one type of protocol in another. Tunneling is the way in which higher-layer data is transported over VPNs by Layer 2 protocol.
unicast address
A type of IPv6 address that represents a single node on a network.
vim text editor
The text editing utility in Linux that allows a technician to make changes to text files, such as when editing the IP address range for a DHCP server.
well-known port
The TCP/IP port numbers 0 to 1023, so named because they were long ago assigned by Internet authorities to popular services (for example, FTP and Telnet), and are, therefore, well known and frequently used.
zone file
A text file associated with a DNS zone that contains resource records identifying domains and their IP addresses.
zone ID
A % sign and a number at the end of an IPv6 address that is used to identify the link the computer belongs to.
zone transfer
In DNS, the act of copying a primary name server’s zone file to the secondary name server to ensure that both contain the same information.
What does the application level deal with?
FQDN, computer names and host names
Describe the Transport layer?
recall that a port number identifies one application among several applications that might be running on a host and is used by the Transport layer
Network layer
An IP address is assigned to every interface
IPv4 (Internet Protocol version 4)
addresses have 32 bits and are written as four decimal numbers called octets, for example 92.106.50.200
IPv6 (Internet Protocol version 6)
addresses have 128 bits
Data Link layer MAC address
also called physical address, is embedded on every NIC on the globe and is assumed to be unique to that NIC.
What ICANN-approved TLDs are there without restrictions?
.com, .org, and .net
What ICANN-approved TLDs are there that are restricted?
.arpa, .mil, .int, .edu, and .gov
