Question | Answer |
address resource record | a type of dns data record that maps the ip address of an internet connected device to its domain name |
alias | nickname for a nodes host name |
anycast address | IPv6 address |
arp table | a database of records that maps mac addresses to ip addresses |
arp | tcp/ip protocol that belongs in the network layer of the osi model |
arp | obtains the mac address of a host,or node and then maps the mac address to the hosts ip logical address |
tcp/ip protocol suite | referred to ip or tcp ip |
tcp/ip advantage | open in nature, flexible routable |
tcp/ip advantage | run on any platform |
tcp/ip advantage | costs nothing,code can be edited and modified by any programmer |
tcp/ip advantage | transmissions carry network layer addressing information |
tcp/ip model | application layer,transport layer,internet layer,network interface,or link, layer |
application layer | http,ftp,telnet,ntp,dhcp,ping |
transport layer | tcp,udp |
internet layer | ip,arp,icmp,igmp |
network interface layer | ethernet |
transmission control protocol | provides reliable data delivery services |
transmission control protocol | connection oriented |
transmission control protocol | uses sequencing and checksums |
transmission control protocol | provides flow control |
transmission control protocol | tcp segment format,the entity that becomes encapsulated by the ip packet in the network layer,becomes the ip packet |
tcp provides flow control | to ensure that a node is not flooded with data |
sequencing | assembled back into the right order |
user datagram protocol | connectionless protocol |
udp | no guarantee that the user will get the data |
udp | more efficient for carrying messages that fit within one data packet |
three segments establish connection | three way handshake syn synack ack |
udp | no error checking or sequencing |
udp advantage | great volume of data transferred quickly |
internet protocol | provides information about how and where data should be delivered,including data source and destination address |
internetwork | transverse more than one lan segment and more than one type of network thru a router |
packets | datagrams |
ip packet | acts as an envelope for data and contains info necessary for routers to transfer data between different lan segments |
two versions of ip protocols | ipv4 and ipv6 |
ipv4 | unreliable,connectionless protocol |
ip protocol | network layer protocol |
ip packet | data envelope |
data envelope | address on envelop,where it is going and where it came from |
ipv6 advantages | provides billions of additional ip addresses |
ipv6 advantages | better security and prioritization provisions |
ipv6 | ip next generation |
ipv6 | released in 1998 |
fields in an ipv4 packet | fifteen |
ipv4 packet fields | version,internet header length,differentiated services,total length |
ipv4 packet fields | identification,flags,fragmentation offset |
ipv4 packet fields | time to live,protocol,headerchecksum,source ip address |
ipv4 packet fields | destination ip address,options,padding,data |
ipv6 packet fields | version,traffic class,flow label |
ipv6 packet fields | payloader length,next header,hop limit |
ipv6 packet fields | source address,destination address |
one major difference between ipv4 and ipv6 | ipv6 packets accommadate the much longer ipv6 addresses |
IPv4 protocols | igmp,arp |
IPv6 protocol | icmp version6 |
internet group management protocol | manages multicasting on networks |
multicasting | transmission method that allows one node to send data to a defined group of nodes |
multicasting | point to multipoint method |
multicast transmission | does not necessarily transmit to every node on a segment |
time to live | in ipv4 is defined as hops or miliseconds |
one node needs to know the mac address of another node on the same network | the first node issues a broadcast message asking, "whose mac address belongs to ip address 1.2.3.4", using arp |
arp table | arp cache |
arp table | a database saved on the hard drive that maps mac addresses to ip addresses |
arp table entries | static and dynamic |
static arp table entries | manually entered addresses |
dynamic arp table entrry | created when a client makes an arp request that cannot be satisfied by data already in the arp table |
ICMPv6 | detects and reports data transmission errors,discovers other nodes on a network,and manages multicasting |
logical addresses | manually or automatically assigned and must follow rules et by the protocol standards |
internet protocol | protocol responsible for logical addressing |
an ip address contains two types of info | network and host |
class d addresses | reserved for multicasting |
class e addresses | reserved for experimental use |
bytes | size |
bits | speed |
node | any device that connects up to a network |
internet control message protocol | network layer core protocol that reports success or failure of data delivery |
broadcast address | last address available in a network |
ip address | unique thirty two bit number |
ip address | thirty two bit number address divided into four octets,or sets of eight bits |
network class | determined from first octet |
Class A | 126 networks |
Class B | less than 16,000 |
Class C | less than two million |
Class A | 1 - 126 |
Class B | 128 - 191 |
Class C | 192 - 223 |
network ID | the portion of an IP address common to all nodes on the same network or subnet |
ipv4 address | four byes long |
loopback address | 127.0.0.1 |
loopback address | ping your own machine |
last address | always broadcast address cant assign it |
zero | reserved as a placeholder |
dotted decimal notation | the shorthand conventionused to represent ipv4 address and make them easier for humans to read |
loopback address | assures that tcp ip suite of protocols in installed, is there an issue with my neywork card |
dotted decimal notation | decimal number between 0 and 255 represents each octet |
dotted decimal address | 131.65.10.36 |
subnetting | a process of subdividing a single class of networks into multiple,smaller logical networks or segments |
subnet mask | thirty two bit number identifying a devices subnet |
subnet mask | informs network about a segment,network where device is attached |
subnet mask | assigned the same way as ip addresses,manually and automatically |
subnets are composed of thirty two bits | four octets and can be expressed in binary or decimal |
ipv6 | composed of 128 bits |
ipv6 | composed of eight 16-bit fields |
ipv6 | typically represented in hexadeciaml numbers |
unicast address | represents a single interface on a device |
multicast address | represents multiple interfaces on multiple devices |
anycast address | represents any one interface from a group of interfaces,any one of which can accept a transmission |
link local unicast address | FE80 |
site local unicast address | FEC0 |
multicast address | FFOx |
ipv6 loopback address | 0:0:0:0:0:0:0::1 |
anycast address | useful for identifying all of the routers that belong to one ISP |
multicast address | useful for transmitting the same data to many different devices simultaneously |
dhcp | automated means of assigning a unique ip address to devices on a network |
reasons for implementing dhcp | reduce the time and planning spent on ip address management |
reasons for implementing dhcp | reduce the potential for errors in assigning ip addresses |
reasons for implementing dhcp | to enable end users to move their workstations and printers without having to change their tcp/ip configuration |
reasons for implementing dhcp | to make ip addressing transparent for mobile users |
IANA | |
ICANN | |
RIRs | |
node | every device connected to something on the network |
static ip addresses | manually assigned |
change static ip address | modify client workstation tcp/ip properties |
dynamic ip address | assigned automatically |
dhcp leasing process | assigns an ip address on a temporary basis for a specified length of time,borrow |
dhcp scope | range of addresses |
dynamic host configuration protocol | application layer protocol |
dhcp | works on first come first serve |
lease time | determined when client obtains ip address at logon |
dhcp service configuration | specified leased address range |
terminating a dhcp lease | expire based on a period established in server configuration |
circumstances requiring lease termination | dhcp server fails and replaced |
dhcp services run on several server types | installation and confihurations vary |
link local address | private addres |
link local address | capable of transmitting and receiving data only on a local network segment |
link local address | are not routable and do not allow nodes to communicate beyond their segments |
private addresses | allow host to communicate on an internal network,intranet |
zero configuration | collection of protocols that assigns link local addresses,performs dns functions,and discovers services |
router | connects two different networks |
ipv4ll | a protocol that manages automatic address assignment among locally connected nodes |
link local | same as apipa |
socket | a processes port number plus its host machine's ip address |
the use of port numbers simplifies | tcp/ip communications and ensures that data are transmitted to the correct application |
well known ports | 0 to 1023 |
registered ports | 1024 to 49151 |
private ports | 49152 to 65535 |
well known ports | are assigned to processes that only the operating system or an administrator of the system can access |
registered ports | are accessible to network users and processes that do not have special administrative privileges |
private ports | are open for use without restriction |
private ports | dynamic ports |
port numbers | simplify tcp/ip communications;ensures data transmitted correctly |
socket address | 10.43.3.87.:23 |
sockets form virtual connections between | a process on one computer and the same process running on another computer |
host | technically every device on the internet |
domain | group of computers belonging to the same organization and has part of their ip addresses in common |
full qualified domain name | local host name plus its domain name |
domain name | www.google.com |
com | top level domain |
google | second level domain |
www | third level domain |
maximum of 253 characters | domain names |
host file | a text file that associates tcp/ip host names with ip addresses |
label | character string |
label | represents level in domain naimg hierarchy |
ICANN | established domain naming conventions |
resolvers | are any hosts on the internet that nned to look up domain name information |
domain name system | a heirarchial way of tracking domain names and their addresses, |
dns | does not rely on one file or even one server,but is distributed over several key computers |
dns | tcp/ip service that belongs to the application layer |
dns service | relies on many computers across he globe |
to direct traffic efficiently | the dns service is divided into three components |
dns components | resolvers, name servers, name spaces |
name servers | servers that contain databases of associated names and ip addresses and provides this information to resolvers onrequest |
namespace | refers to the database of internet ip addresses and their associated names |
namespace | abstract concept that describes how the name servers of the world share dns information |
dns zones | portions for which one organizaion is assigned authority to manager |
zone file | information about hosts in a dns zone |
root server | a dns server maintained by icann and iana that is an authority on how to contact the top level domains |
root server | icann oversees 13 root servers |
resolver | anything that can connect to the internet and look up information |
dns cache | a database stored on your computer that stores information about ip addresses and their associated host names |
name servers | provides info to resolvers on request |
zone transfer | copying the primary name server's zone file to the secondary's name server |
most organizations rely on two name servers | primary and secondary |
dns - static | reliable way of locating a host as long as the hosts ip address remains relatively constant over time |
telnet | port 23 |
telnet | used to log on to remote hosts using the tcp/ip protocol suite |
ftp | port 20 and 21 |
ftp | used to send and receive files via tcp/ip |
ftp | a set of simple commands that make up their user interfaces |
tftp | port 69 |
tftp | enables file transfers between computers |
dynamic dns | service provider runs program on users computer |
ddns | service providers server launches routine to automatically update dns record |
tftp | connectionless protocol |
tftp | useful when you need to load data or programs on a computer that lacks a hard drive |
trivial file transfer protocol | diskless workstation |
network time protocol | port 123 |
ntp | synchronize the clocks of computers on a network |
ping | packet internet groper |
tcp | connection oriented |
telnet | insecure |
pinging | send a signal back and forth |
ping | often employed simply to determine whether a host is up or down |
ping | uses icmp |
ftp | host running ftp server portion |
difference between ftp and tftp | tftp does not allow directory browsing |
ping switches | ? |
ping switches | a |
ping switches | n |
ping switches | r |
? | displays the help text for ping command |
a | when used with an ip address, resolves the address to a host name |
n | allows you to specify a number of echo requests to send |
r | when used with a number from one to nine displays the route taken during ping hops |
time synchronization importance | maintaining accuracy,consistency between multiple storage systems |
ping | provides verification |
ping | send echo request and echo reply messages |