Networks Test 2
crossover cable orientation
1->3 2->6 4->4 5->5 7->7 8->8
Types of protocols that transport data over networks
1. TCP (connection oriented) 2. UDP (connectionless)
Features you want in Serves OS package
1. want to be able to manage users, hardware, and software (LDAP 2. file/hardware serving 3. scalable 4. connectivity 5. fault tolerence 6. security 7. include/add-in: web server email server streaming media Remote access server 8. virtualization
What are the IPv4 addresses for a private network?
10.X.X.X 172.16.X.X - 172.31.X.X 192.168.X.X (usually a home network)
802.11b
11 Mbps 2.4 GHz about 35 meters can configure specific channels
IPv6
128 bit address broken into 8 groups of 16 bits each. Reported as 8 groups of 4 Hex numbers, separated by semicolons
The TCP/IP port used for SFTP is ____________ and for FTP is ______________ .
22 / 21
802.11n
300 Mbps 2.4 of 5 GHz about 70 meters newer and quickly overtaking 802.11g in popularity
802.11g
54 Mbps 2.4GHz about 35 meters widely depolyed
What is a private network
A private IP address is an IP address that's reserved for internal use behind a router or other Network Address Translation (NAT) device, apart from the public.
______________________________________ is used to resolve an IP address to MAC address.
ARP
ARP
Address Resolution Protocol uses broadcast transmissions to identify the MAC address of computers the IP address routes the traffic to the correct subnet, when the subnet is reached, the ARP protocol broadcasts the IP address to all computers on the subnet
_______________________________________ is a protocol that lets network administrators manage centrally and automate the assignment of IP addresses in an organization's network
DHCP
DHCP
Dynamic Host Configuration Protocol protocol that automates the assignment of IP addresses within a network when machines request them
EMI
Electromagnetic interference interference caused by machinery or electrical devices or natural phenomena such as electrically charged raindrops when the EMI reaches a computer or network, it can interfere and degrade signals when interference is significant, data transmissions are blocked common source of EMI is devices with motors, laser printers, microwave ovens
FTP
File Transfer Protocol used to upload and download files to and from computer on the Internet and within some internal networks uses TCP for guarenteed delivery of the files can access FTP from command prompt
Why is virtualization software important?
Having it on one complete file allows you to move it around and use it on different machines as needed, and virtualization is cheaper in the long run.
HTTP
Hypertext Transfer Protocol defines how files on the World Wide Web (WWW) are formatted, transmitted, and rendered in web browsers HTTP = port 80 HTTPS = port 443
sockets
IP address with the port number to access that port on the browser (ex: 10.30.20.2:80)
IANA Purpose
Internet Assigned Numbers Authority is a department of ICANN that controls the regulation of port numbers for standardization
ICANN
Internet Corporation for Assigned Names and Numbers organization that controls and assigns all public IP addresses and authorizes all domain names.
IMAP
Internet Message Access Protocol email protocol more commonly used on internal networks rather than on the internet current version is IMAP4 difference between POP3 and IMAP4: messages are not automattically downloaded to the client and can be retained on the server with IMAP4 - IMAP4 servers allow users to view email message headers individually and choose hich to open
_____________________________ is the primary authentication protocol used within a Microsoft domain.
Kerberos
Layer 2 Tunneling Protocol
L2TP VPN protocol combination of the Layer 2 Forwarding (L2F) protocol from Cisco and PPTP FROM MICROSOFT IPSec is used with L2TP to provides security for the VPN connection L2TP = UDP port 1701
LDAP
Lightweight Directory Access Protocol used to query directories such as Microsoft's Active Directory Domain Services allows individuals to query the directory to locate and manage resources within the domain transmits data across the network in clear text SLDAP sues SSL or TLS to prevent attackers from using sniffers to capture data SLDAP uses digital certificate for authentication LDAP = port 389 SLDAP - port 636
Packets have two sets of addresses
MAC Addresses IPv4 Addresses
Use for IP addresses
Needed in order to send any data from one machine to another. No IP addresses = no data transmission
IP Address has two components:
Network ID and host ID
IP Address has two parts:
Network ID/Host ID Subnet ID
What is the difference between POP3 protocol and IMAP protocol?
POP3 protocol deleted emails from a server IMAP leaves the email on the server
Point-to- Point Tunneling Protocol
PPTP VPN protocol provides a secure connection over a public network such as the internet primarily used in microsoft networks PPTP = port 1723
POP3
Post Office Protocol v3 protocol used to retrieve email from an email server
________________________________________ is a windows client application that allows an authorized user to use SSH to connect to a remote device.
PuTTY
Among other uses the ___________________________________ protocol allows a help-desk professional to take control of a user's desktop and provide assistance.
ROS
RFI
Radio frequency interfernece interference from broadcasted radio signals when a transmitter is close enough and/or transmits the signals at high enough amplitudes, unintended systems can pick it up Sources of RFI: cordless phones, bluetooth devices
RDS
Remote Desktop Services add on to microsoft windows servers can host applications or entire desktops that are accessible to users on the network
protocol used to send e-mail is ___________________________________________________.
SMTP
_____________________________________ is an encryption protocol that creates a secure encrypted session and has replaced the non-secure Telnet protocol.
SSH
SSH
Secure Shell encryption protocol that creates a secure encrypted session that can be used by other protocols example: SFTP is FTP encrypted with SSH has replaced telnet in many applications SSH is more secure than telnet and more suitable for use on the internet
SSL
Secure Sockets Layer encryption protocol used for a wide assortment of purposes SSL protects HTTP as HTTPS provides security in: confidentiality Integrity Authentication uses digital certificates for confidentiality, integrity, and authentication VPNs have emerged using SSL as a tunneling protocol
SMTP
Simple Mail Transfer Protocol primary protocol used to deliver email over the internet and within internal networks email servers use SMTP to send and recieve email between each other user systems use SMTP to send email to SMTP servers
SNMP
Simple Network Management Protocol management protocol used to manage network devices such as routers and swithces many different applications are available that use SNMP SNMP - UDP port 161
Connection Oriented Protocol
TCP starts with an establishes session using a three-way handshake process. This three way handshake process ensures a connection is established before data is transmitted. TCP: connection oriented using ports and sockets
One of its primary uses of the protocol _______________________________ is to boot a diskless device into a local area network from a server.
TFTP
Connectionless Protocol
UDP sends data using a best-effort method. it doesn't establish a session, so it doesn't provide guaranteed delivery UDP: connectionless protocol used to send short messages, or datagrams in a network
Reasons to tunnel
VPN, so that private packet is sent within a public packet. Software removes the outside packet so that the private packet can enter the private network. IPv6 traffic can travel on IPv4 line by having IPv6 packet within the payload of IPv4 packet.
Valid IPv4 Addresses
Valid IP addresses have four decimals separated by three dots only valid decimal number are 0-255
VPN
Virtual Private Network provides access to an internal network over a public network such as the internet the client accesses the internet using any available means - the client then connects to the VPN server, which is reached through the internet - after authenticationg with the server, the VPN server provides connectivity to the internal network. The VPN server is accessible to any client that has access to the internet
VoIP
Voice over IP streaming media such as streaming audio, video, and VoIP all use UDP delivers voice communications and multimedia over the internet
power surge
a power surge last longer than a power spike and is usually less of an increase in voltage may be only about 20% above normal but will last around a minute
power spikes
a short duration increase in voltage it can cause damage to equipment most common source: lightning strikes
APIPA
address always starts with169.254.x.x subnet mask is always 255.255.0.0 Automatic Private Internet Protocol Addressing the APIPA address provides limited connectivity for clients on the network
what makes a network private
addresses are assigned internally and not known to the outside world. Have to be converted to public before entering or leaving the network. Lots of security
wireless advantages/disadvantages
advantages: cheaper, mobile, quick setup disadvantages: interference and straight line of sight needed, lower security, cannot span a long distance
How do you determine the default gateway?
all the computers in subnet A will be configured with a default gateway of 192.168.1.1 and the computers in subnet B will be configured with a default gateway of 192.168.4.1 End with a 1 because often assigned the first IP address available beyond the subnet ID. Ex: 172.16.30.1 for a subnet ID of 172.16.30.
difference between server software and client software
client software only allows connection to network and does not have any networking capabilities Server software allows you to manage all hardware, software, and users in a network as well as access to that network. Usually on a dedicated machine.
Telnet
command-line interface that allows bidirectional communication with network devices and other systems on the network all commands are typed at a command prompt instead of using point-and-click methods within a windows GUI benefit: allows terminal emulation (can connect remotely) sessions include: telenet server, client, window (command prompt), and a transferring protocol
purpose and advantages of UTP categories
connecting machines to a network inside buildings Advantages: cheaper, easier to work with and maneuver Disadvantages: vulnerable to RFI and EMI
connection oriented protocol vs. connectionless
connection oriented have confirmation sent that a packet has been received by receiving machine, while connectionless sends data and does not receive confirmation, but sends with best efforts
opening and closing ports with a firewall
control panel -> windows firewall -> Allow a program or feature through windows firewall -> change settings -> HTTP (port 80)
Cross talk
data that crosses from one transmission line to another can result in a degraded signal or data jumping from one wire to another results in two prolbems: corruption of data loss of confidentiality
Network limitations
distance data transfer rates line of sight twists pre-foot etc
DNS
domain naming system service that resolves host names to IP addresses clients send name resolution requests to a DNS server adn the DNS server responds with the IP addresses
Fiber Optics - where found, advantages, disadvantages
either glass or a type of plastic that carries light pulses lost of benefits over twisted pair, but more expensive can carry signals up to 40 km advantages: immune to interference immune to crosstalk interception is difficult lightweight disadvantages: expensive tough to work with need converter to go from electrical to light signal outdoors and in between buildings for longer distances
Problems with connectivity
electromagnetic interference radio frequency interference power spikes interception of signals fire hazards cross talk
Windows 2016 server three versions:
essential standard data center
purpose of network or subnet ID
identifies the subnetwork, or subnet where the computer is located network ID is always expressed with trailing zeros portion of the IPv4 address that is used to identify the network of the machine sending or receiving the data.
firewall problems
important for security, open and close ports as a security measure to control traffic.
purpose of subnet mask
in internal networks, IP addresses are accompanies by a subnet mask subnet mask identifices the portion of the IP address that is the network ID common subnet masks: 255.0.0.0 255.255.0.0 255.255.255.0 TCP/IP uses the subnet mask to determine which portion of the IP address is the netwrok ID and which portion is the HOST ID when the subnet mask is configured at its maximum value (255), that indicated that the corresponding portion of the IP address is part of the network ID and the remaining portion of the IP address is the host ID consider an IP address of 192.168.1.5 with a subnet mask of 255.255.255.0 - since the first three decimals of the subnet mask are 255, the first three decimals of the IP address make up the network ID used determine what part of the 32 bit IP address is the subnet ID and what part is the host ID. Must know subnet mask to determine if machine is local or remote
power sags
occurs when the AC voltage falls below normal for a period of time when a DC power supply doesn't receive enough AC power, it can't provide enough DC power to the internal system results in the system turning off
encapsulating packets
one packet as the payload in another packet, usually with encryption
kerberos
primary authentication protocol used within a microsoft domain and is managed as part of active directory helps guard the secrets within active directory uses complex process of issuing time-stamped tickets to users after the log on - users present these tickets when tryhing to access resrouces - if tickets are valid, access is granted uses symmetric cryptography to encrypt tickets Kerberos = port 88
surge protector
protects against power spikes and surges. if excessive voltage reaches the surge protector, a built in circuit breaker pops and prevents the voltage from reaching the equipment have different ratings based on response time and power threshold sensitivity
Twisted Pair - where found, advantages, disadvantages?
single cable with four pairs of copper wires twisted around each other distance = 100 meters (can use repeaters to extend distance
IPv4
standard IP addressing scheme since the 1980s it's used to get TCP/IP traffic from one computer to another computer over a network
straight through cable versus cross over cable
straight through cable: pin 1 in one connector is wired to pin 1 in the other connector, pin 2 is wired to pin 2, etc. connect dissimiliar devices on the network example: a computer connected to a hub, switch, or router would use a straight through cable Cross over cable: connect similiar devvices to each other have specific pins in one connector crossed over to differenct pins in the other connector straight thru used from machine to switch. Switch crosses the connection before sent to the receiving machine
Default Gateway
the IP address of the router on the local subnet the default gateway will usually provide a pther to the internet
Why do you need IPv6
there are only about 3.7 billion IP addresses and IPv6 is 128 bits, which provides much room for growth. (trillion of trillions more IP addresses other advantages: native support for IPSec More efficient routing Easy host configuration
A ________________________________ protocol allows a foreign or non -encrypted packet to be encapsulate in another packet for part of the data transmission.
tunneling
tunneling
tunneling is embedding a packet as a payload in another packet, usually with encryption private networks can now send things through public networks without knowing that they are from private networks Example: tunneling a IPv6 packet in a IPv4 packet so it works better
UPS
uninterruptible power supply provides continous power to a system even if a power sag occurs or if power is lost for a short period primary purpose is to provide power to a system by battery long enough to complete a logical shutdown or for generators to come online and stablize not inteended as a long-term power source
Purpose of host ID
uniquely identifies the computer within a subnet the host ID is whatever remains after identification of the network ID portion of the IPv4 address that is used to identify the machine sending or receiving the data.
