2,0 Networking Flashcards
A series of moving vans(IP)
* Efficiently move large amounts of data
– Think of this as like a :
- The network topology is the road
– _____ system - The truck is the Internet Protocol (IP)
– Hint: roads - The boxes hold your data
– Boxes of ____and ___ - Inside the boxes are more things
– ___ information
-a shipping truck
*
-Ethernet, DSL, cable system
*
-We’ve designed the roads for this truck
*
-TCP, UDP
*
-Application information
TCP and UDP
* Transported inside of IP
– Encapsulated by the ____
* Two ways to move data from place to place
– Different _____ for different ____
* OSI Layer 4
– The ____ layer
* Multiplexing
– Use many different _____ at the same time
– __P and __P
-IP protocol
*
-features, applications
*
-transport
*
-applications
-TCP, UDP
TCP – Transmission Control Protocol
* Connection-oriented
– A formal connection ___and ___
* “Reliable” delivery
– Recovery from ____
– Can manage out-of-order ____ or ____
* Flow control
– The receiver can manage how much ____ is sent
- A formal connection setup and close
*
-Recovery from errors
-Can manage out-of-order messages or retransmissions
*
-The receiver can manage how much data is sent
UDP – User Datagram Protocol
* Connectionless - No formal open/close to the connection
* “Unreliable” delivery
– No ___ recovery
– No reordering of ___ or ____
* No flow control
– Sender determines the amount of data ____
– No error recovery
– No reordering of data or retransmissions
*
– Sender determines the amount of data transmitted
Why would you ever use UDP?
* Real-time communication
– There’s no way to ___ and ___ the data
– Time doesn’t stop for your ___
* Connectionless protocols
– DHCP (_____)
– TFTP (____)
– There’s no way to stop and resend the data
– Time doesn’t stop for your network
*
– DHCP (Dynamic Host Configuration Protocol)
– TFTP (Trivial File Transfer Protocol)
Communication using TCP
* Connection-oriented protocols prefer a “return receipt”
– HTTPS (Hypertext Transfer Protocol Secure)
– SSH (Secure Shell)
* The application doesn’t worry about out of order
frames or missing data
– TCP handles all of the ________ overhead
– The application has ____ job
-Hypertext Transfer Protocol Secure
-Secure Shell
*
-communication
-one
Speedy delivery
* The IP delivery truck delivers from one _____ address to
another (IP) address
– Every house has an address, every computer
has an IP address
* Boxes arrive at the house / IP address
– Each box has a ___ name
* Port is written on the outside of the box
– Drop the box into the right ____
-Every house has an address, every computer
has an IP address
*
-Each box has a room name
*
-Drop the box into the right room
Lots of ports
* IPv4 sockets
– Server IP address, _____l,
server application ___ number
– Client IP address, protocol, client ____ number
Lots of ports
* Non-ephemeral ports – permanent port numbers
– Ports 0 through 1,023
– Usually on a server or service
Lots of ports
* Ephemeral ports – temporary port numbers
– Ports ____ through ____
– Determined in _____ by the client
– Server IP address, protocol,
server application port number
– Client IP address, protocol, client port number
*
-Ports 0 through 1,023
– Usually on a server or service
*
– Ports 1,024 through 65,535
– Determined in real-time by the client
Port numbers
* TCP and UDP ports can be any number between
0 and 65,535
* Most servers (services) use non-ephemeral
(not-temporary) port numbers
– This isn’t ___ the case
– It’s just a ___.
* Port numbers are for communication, not security
* Service port numbers need to be “well known”
* TCP port numbers aren’t the same as UDP port numbers
– This isn’t always the case
– It’s just a number.
Port numbers
* Well-known port number
– Client and server need to ____
- Important for firewall rules - Port-based security
- A bit of rote memorization
– Becomes second nature after a while - Make sure you know port number, protocol,
and how the protocol is used
– Client and server need to match
*
– Becomes second nature after a while
FTP - File Transfer Protocol
* tcp/20 (active mode data), tcp/21 (control)
– Transfers files ___ systems
* Authenticates with a username and password
– Some systems use a _______ login
* Full-featured functionality - List, add, delete, etc
– Transfers files between systems
*
– Some systems use a generic/anonymous login
SSH - Secure Shell
- Encrypted communication link - tcp/22
* Looks and acts the same as Telnet
- Encrypted communication link - tcp/__
Telnet
- Telnet – Telecommunication Network - tcp/__
* Login to devices remotely
– ____ access
Telnet
* In-the-clear communication
– Not the best choice for ___ systems
- Telnet – Telecommunication Network - tcp/23
*
– Console access
*
– Not the best choice for production systems
SMTP - Simple Mail Transfer Protocol
* SMTP - Simple Mail Transfer Protocol
– Server to server email transfer - tcp/25
* Also used to send mail from a device to a mail server
– Commonly configured on mobile devices and email clients
* Other protocols are used for clients to receive email
– I___, P___
– Server to server email transfer - tcp/25
*
-Commonly configured on mobile devices and email clients
*
-IMAP, POP3
DNS - Domain Name System
* Converts names to IP addresses - udp/53
– www.professormesser.com = 162.159.246.164
* These are very critical resources
– Usually multiple ___ servers are in production
- www.____.com = __.__
*
– Usually multiple DNS servers are in production
DHCP - Dynamic Host Configuration Protocol
* Automated configuration of IP address, subnet mask and
other options - udp/67, udp/68
– Requires a ___ server
– Server, appliance, integrated into a ___ router, etc.
DHCP - Dynamic Host Configuration Protocol
* Dynamic / pooled
– IP addresses are assigned in ___-____ from a pool
– Each system is given a lease and must renew at __ intervals
DHCP - Dynamic Host Configuration Protocol
* DHCP reservation
– Addresses are assigned by ___ address in the ___ server
– Manage addresses from ___ location
– Requires a DHCP server
– Server, appliance, integrated into a SOHO router, etc.
*
– IP addresses are assigned in real-time from a pool
– Each system is given a lease and must renew at set intervals
*
– Addresses are assigned by MAC address in the DHCP server
– Manage addresses from one location
HTTP and HTTPS
* Hypertext Transfer Protocol
– Communication in the ___
– And by other ____
* In the clear or encrypted
– Supported by nearly all web __ and ___
– Communication in the browser
– And by other applications
*
– Supported by nearly all web servers and clients
POP3 / IMAP
* Receive emails from an email server
– Authenticate and transfer
* POP3 - Post office Protocol version 3
– tcp/___
– Basic mail ___ functionality
* IMAP4 - Internet Message Access Protocol v4
– tcp/___
– Includes email ____ management from multiple clients
– Authenticate and transfer
*
– tcp/110
– Basic mail transfer functionality
*
– tcp/143
– Includes email inbox management from multiple clients
SMB - Server Message Block
* Protocol used by Microsoft Windows
– File ____, printer ___
– Also called CIFS ()
SMB - Server Message Block
* Using NetBIOS over TCP/IP
(Network Basic Input/Output System)
– __/137 - NetBIOS name services (nbname)
– __/139 - NetBIOS session service (nbsession)
* Direct over tcp/445 (NetBIOS-less)
– Direct SMB communication over TCP without
the ____ transport
– File sharing, printer sharing
– Also called CIFS (Common Internet File System)
SMB - Server Message Block
*
– udp/137 - NetBIOS name services (nbname)
– tcp/139 - NetBIOS session service (nbsession)
*
– Direct SMB communication over TCP without
the NetBIOS transport
SNMP - Simple Network Management Protocol
* Gather statistics from network devices
– Queries: udp/16_
– Traps: udp/16_
SNMP - Simple Network Management Protocol
* v1 – The original
– _____ tables
– In-the-____
SNMP - Simple Network Management Protocol
* v2 – A good step ahead
– Data type enhancements
– ___ transfers
– Still in-the-____
SNMP - Simple Network Management Protocol
* v3 – A secure standard
– Message ___
– _____tion
-______ption
– Queries: udp/161
– Traps: udp/162
*
– Structured tables
– In-the-clear
*
– Data type enhancements
– Bulk transfers
– Still in-the-clear
*
– Message integrity
– Authentication
– Encryption
LDAP
* LDAP (Lightweight Directory Access Protocol) - tcp/389
* Store and retrieve information in a network directory
– Commonly used in Microsoft Active ___
-Microsoft Active Directory
RDP - Remote Desktop Protocol
-Share a desktop from a remote location over tcp/3389
* Remote Desktop Services on many Windows versions
-Can connect to an entire ___ or just an a_____
* Clients for Windows, macOS, Linux, Unix, iPhone,
Android, and others
-Share a desktop from a remote location over tcp/3389
*
-Can connect to an entire desktop or just an application
Network devices
* Many different devices and components
– All have different ___
Network devices
* Some of these functions are combined together
– Wireless r____/s___/fi___
Network devices
* Compare different devices
– Understand when they should be _
– All have different roles
*
– Wireless router/switch/firewall
*
– Understand when they should be used
Routers
* Routes traffic between IP subnets
– Makes forwarding decisions based on IP address
– Routers inside of switches sometimes called
“layer 3 switches”
Routers
* Often connects diverse network types
-L___, W___, co___, f____r
– Makes forwarding decisions based on IP address
– Routers inside of switches sometimes called
*
-L___, W___, co___, f____r
– LAN, WAN, copper, fiber
Switches
* Bridging done in hardware
– Application-specific _____ circuit (ASIC)
– Forwards traffic based on ___ link address
- Many ports and features
– The core of an _____ network
– May provide _____ over ______ (PoE) - Multilayer switch
– Includes ______ functionality
– Application-specific integrated circuit (ASIC)
– Forwards traffic based on data link address
*
– The core of an enterprise network
– May provide Power over Ethernet (PoE)
Switches
*
– Includes routing functionality
Unmanaged switches
* Very few configuration options
– ___ and play
Unmanaged switches
* Fixed configuration
– No ___Ns
Unmanaged switches
* Very little integration with other devices
– No ____ protocols
Unmanaged switches
* Low price point
– Simple is less ____
– Plug and play
*
– No VLANs
*
– No management protocols
*
– Simple is less expensive
Managed switches
* VLAN support
Managed switches
– Interconnect with other switches via 802._ _
- Traffic prioritization
– Voice traffic gets a _____ priority - Redundancy support
– S____Tr___ Protocol (STP) - Port mirroring
– ______ packets - External management
– Simple _____ _____ Protocol (SNMP)
– Interconnect with other switches via 802.1Q
*
– Voice traffic gets a higher priority
*
– Spanning Tree Protocol (STP)
*
– Capture packets
*
– Simple ____ _____ Protocol (SNMP)
Access point
* Not a wireless router
– A wireless router is a router and an access point
in a single device
Access point
* An access point is a bridge
– Extends the wired network onto the wireless network
– Makes forwarding decisions based on ____ address
– A wireless router is a ___r and an a____ point
in a single device
*
– Extends the ____ network onto the wireless network
– Makes forwarding decisions based on MAC address
Patch Panels
* Combination of punch-down blocks and
RJ-45 connectors
* Runs from desks are made once
– Permanently ___ down to ____ panel
Patch Panels
* Patch panel to switch can be easily changed
– No ____ tools
– Use ____ cables
– Permanently punched down to patch panel
Patch Panels
*
– No special tools
– Use existing cables
Firewalls
* Filters traffic by port number
– OSI layer 4 (___P/____P)
– Some firewalls can filter based on the ___
- Can encrypt traffic into/out of the network
– Protect your traffic ____ sites - Can proxy traffic
– A common ____ technique - Most firewalls can be layer 3 devices (routers)
– Usually sits on the ___ess/__gress of the network
– OSI layer 4 (TCP/UDP)
– Some firewalls can filter based on the application
*
– Protect your traffic between sites
*
– A common security technique
*
– Usually sits on the ingress/egress of the network
Power over Ethernet (PoE)
* Power provided on an Ethernet cable
– One wire for both _____ and electricity
– Phones, cameras, _____s access points
– Useful in ____-to-power areas
Power over Ethernet (PoE)
* Power provided at the switch
– Built-in power - ___spans
– In-line power injector - ___dspans
– One wire for both network and electricity
– Phones, cameras, wireless access points
– Useful in difficult-to-power areas
*
– Built-in power - Endspans
– In-line power injector - Midspans
PoE switch
* Power over Ethernet
– Commonly marked on the __ch or i___
– Commonly marked on the switch or interfaces
PoE, PoE+, PoE++
* PoE: IEEE 802.3af-2003
– The original ___ specification
– Now part of the 802.__ standard
– 15._ watts DC power, 3___ mA max current
* PoE+: IEEE 802.3at-2009
– Now also part of the 802._ standard
– 25._ watts DC power, 60_ mA max current
* PoE++: IEEE 802.3bt-2018
– 5_ W (Type 3), 60_ mA max current
– 71._ W (Type 4), 96_ mA max current
– PoE with 10G___E-T
– The original PoE specification
– Now part of the 802.3 standard
– 15.4 watts DC power, 350 mA max current
*
– Now also part of the 802.3 standard
– 25.5 watts DC power, 600 mA max current
*
– 51 W (Type 3), 600 mA max current
– 71.3 W (Type 4), 960 mA max current
– PoE with 10GBASE-T
Hub
* “Multi-port repeater”
– Traffic going in one port is repeated to
every other port
-Everything is ___-duplex
* Becomes less efficient as network traffic increases
* 10 megabit / 100 megabit
* Difficult to find today
– Traffic going in one port is repeated to
every other port
-Everything is half-duplex
Cable modem
* Broadband
– Transmission across multiple ____
– Different ____ types
* Data on the “cable” network
– DOCSIS (_________)
* High-speed networking
– Speeds up to 1 ____/s are available
* Multiple services
– __ta, vo_, v___o
– Transmission across multiple frequencies
– Different traffic types
*
– DOCSIS (Data Over Cable Service Interface Specification)
*
– Speeds up to 1 Gigabit/s are available
*
– Data, voice, video
DSL modem
* ADSL (Asymmetric Digital Subscriber Line)
– Uses ___ lines
* Download speed is faster than the upload
speed (asymmetric)
– ~1,____ foot limitation from the central office (CO)
– 5 Mbit/s downstream / 1_ Mbit/s upstream are
common
– Faster speeds may be possible if closer to the ___
– Uses telephone lines
*
– ~10,000 foot limitation from the central office (CO)
– 52 Mbit/s downstream / 16 Mbit/s upstream are
common
– Faster speeds may be possible if closer to the CO
ONT
* Optical network terminal
– Fiber to the ____
ONT
* Connect the ISP fiber network to the copper network
– ______point (demarc) in the data center
– _____box on the side of the building
ONT
* Line of responsibility
– One side of the box is the ___
– Other side of the box is your ___
– Fiber to the premises
*
– Demarcation point (demarc) in the data center
– Terminal box on the side of the building
*
– One side of the box is the ISP
– Other side of the box is your network
Network Interface Card (NIC)
* The fundamental network device
– Every device on the network has a ___
– Computers, servers, printers, routers, switches,
phones, tablets, cameras, etc.
* Specific to the network type
– E___et, W_N, wireless, etc.
* Often built-in to the motherboard
– Or added as an ___card
* Many options - Single port, multi-port, copper, fiber
– Every device on the network has a NIC
– Computers, servers, printers, routers, switches,
phones, tablets, cameras, etc.
*
– Ethernet, WAN, wireless, etc.
*
– Or added as an expansion card
SDN (Software Defined Networking)
* Networking devices have different functional
planes of operation
– Data, control, and _m____planes
* Split the functions into separate logical units
– Extend the f____y and m____t
of a single device
– Perfectly built for the cloud
* Infrastructure layer / Data plane
– Process the network f__ and p___
– Forwarding, tr___, encrypting, NAT
* Control layer / Control plane
– Manages the actions of the ___plane
– R___ tables, s___ tables, N__ tables
– Dynamic routing protocol ___
– Data, control, and management planes
SDN (Software Defined Networking)
*
– Extend the functionality and management
of a single device
– Perfectly built for the cloud
*
– Process the network frames and packets
– Forwarding, trunking, encrypting, NAT
*
– Manages the actions of the data plane
– Routing tables, session tables, NAT tables
– Dynamic routing protocol updates
Extend the physical architecture
SDN data flows
* Application layer / Management plane
– C___ and m___ the device
– SSH, browser, API
– Configure and manage the device
– SSH, browser, API
Wireless standards
* Wireless networking (802.11)
– Managed by the IEEE L__/M__
Standards Committee (IEEE 802)
* Many updates over time
– Check with I___ for the latest
* The Wi-Fi trademark
– Wi-Fi Alliance handles i_______y testing
– Managed by the IEEE LAN/MAN
*
– Check with IEEE for the latest
*
– Wi-Fi Alliance handles interoperability testing
802.11a
* One of the original 802.11 wireless standards
– October 19__
- Operates in the 5 GHz range
– Or other frequencies with special ___
* 54 megabits per second (Mbit/s)
* Smaller range than 802.11b
– ___frequency is absorbed by objects in the way
* Not commonly seen today
- October 1999
- Operates in the ___ GHz range
– Or other frequencies with special licensing
*
– Higher frequency is absorbed by objects in the way
802.11b(hint: for frequency, think BGs)
* Also an original 802.11 standard - October 1999
- Operates in the ___ GHz range
-____ megabits per second (Mbit/s)
* Better range than 802.11a, less absorption problems
* More frequency conflict
– Baby monitors, cordless phones,
microwave ovens, Bluetooth
* Not commonly seen today
-Operates in the 2.4 GHz range
-11 megabits per second (Mbit/s)
*
– ___ monitors, cordless ___, microwave ovens, Blue___
802.11g (hint: for frequency, think BGs)
* An “upgrade” to 802.11b - June 2003
- Operates in the ___ GHz range
- ___ megabits per second (Mbit/s) (hint: 5 times faster than b)
- Similar to 802.11_
* Backwards-compatible with 802.11b
* Same 2.4 GHz frequency conflict problems as 802.11b
- Operates in the ____ GHz range
- 54 megabits per second (Mbit/s)
- Similar to 802.11a
802.11n (Wi-Fi 4)
* The update to 802.11g, 802.11b, and 802.11a
*October 2009
-Operates at 5 GHz and/or 2.4 GHz
– ____MHz channel widths
* 600 megabits per second (Mbit/s)
– ____ MHz mode and 4 antennas
* 802.11n uses MIMO
– MIMO means?
– Multiple ___ and receive antennas(MIMO)
-Operates at 5 GHz and/or 2.4 GHz
– 40 MHz channel widths
*
– 40 MHz mode and 4 antennas
*
– Multiple-input multiple-output
– Multiple transmit and receive antennas
802.11ac (Wi-Fi 5)
* Approved in January 2014
– Significant improvements over 802.11_
* Operates in the 5 GHz band
– Less ___, more frequencies (up to ___MHz
channel bandwidth)
* Increased channel bonding - Larger bandwidth usage
* Denser signaling modulation
– Faster ___transfers
* Eight MU-MIMO downlink streams
– Twice as many streams as 802.11_
– Nearly _ gigabits per second
– Significant improvements over 802.11n
*
– Less crowded, more frequencies (up to 160 MHz
channel bandwidth)
*
– Faster data transfers
*
– Twice as many streams as 802.11n
– Nearly 7 gigabits per second
802.11ax (Wi-Fi 6)
* Approved in February 2021
– The successor to 802.11ac/Wi-Fi 5
* Operates at 5 GHz and/or 2.4 GHz
– 20, 40, __, and ___ MHz channel widths
* 1,201 megabits per second per channel
– A relatively small ____in throughput
– Eight bi-______ MU-MIMO streams
* Orthogonal frequency-division multiple access (OFDMA)
– Works similar to cellular ____
– Improves high-____installations
– The successor to 802.11ac/Wi-Fi 5
*
– 20, 40, 80, and 160 MHz channel widths
*
– A relatively small increase in throughput
– Eight bi-directional MU-MIMO streams
*
– Works similar to cellular communication
– Improves high-density installations
Long-range fixed wireless
* Wireless access point in a house with the stock antennas
– You might get a range of ___ to 50 meters
* Try connecting two buildings located miles from each other
– Fixed directional ____ and increased signal ____
* Outdoors
– Minimal signal ___ or b____
* Directional antennas
– Focused, point-to-____ connection
* Wireless regulations are complex
– Refer to your country’s _____ agency
* Frequency use
– Unlicensed 2.4 GHz or 5 GHz frequencies
– Additional ____ may be available
– Additional ____ may be required
* Signal strength
– Indoor and outdoor power is usually ____
* Outdoor antenna installation is not trivial
– Get an ___ , be safe
– You might get a range of 40 to 50 meters
*
– Fixed directional antennas and increased signal strength
*
– Minimal signal absorption or bounce
*
– Focused, point-to-point connection
*
– Refer to your country’s regulatory agency
*
– Unlicensed 2.4 GHz or ___ GHz frequencies
– Additional frequencies may be available
– Additional licensing may be required
*
– Indoor and outdoor power is usually regulated
*
– Get an expert, be safe
RFID (Radio-frequency identification)
* It’s everywhere
– Access badges
– Inventory/Assembly line ___
– Pet/Animal ____
– Anything that needs to be ____
* Radar technology
– Radio ___ transmitted to the tag
– RF powers the ___, ID is transmitted back
– Bi_____ communication
– Some tag ____can be active/powered
– Access badges
– Inventory/Assembly line tracking
– Pet/Animal identification
– Anything that needs to be tracked
*
– Radio energy transmitted to the tag
– RF powers the tag, ID is transmitted back
– Bidirectional communication
– Some tag formats can be active/powered
NFC (Near field communication)
* Two-way wireless communication
– Builds on RFID, which is mostly ___-way
* Payment systems
– Major ___ cards, online wallets
* Bootstrap for other wireless
– NFC helps with ___ pairing
* Access token, identity “card”
– Short range with ____ support
-Builds on RFID, which is mostly one-way
*
– Major credit cards, online wallets
*
– NFC helps with ___ pairing
*
– Short range with encryption support
IPv4 addresses format
IPv6 addresses format
DNS Lookup
DNS Hierarchy
