4. Networking Infrastructure Flashcards
2 ways to connect with a LAN
Ethernet and WiFi
Standard Ethernet cable
RJ 45 (8 pin connecter)
Landline phone cable
RJ 11 (6 pin connecter)
WAN
a collection of LANs not tied to one specific location
a PAN is a
Personal Area Network - designed to support a single person (Bluetooth - main purpose is to connect peripherals)
NFC uses
inductive coupling - for payment and access control
Broadband connections are
always on (as opposed to dial-up) and measured in Mbps or Gbps
A modem converts
Digital computer signals to analog for copper wires (and back)
Fiber optic modems use a
laser to convert digital signals to pulses of light to travel through glass
6 types of internet connections
DSL (Digital Subscriber Line); Cable (coaxial), Fiber Optic (glass); Wireless for Mobile; Fixed Wireless (RF), Satellite
5G has speeds
up to 20 Gbps
4G has speeds
up to 14 Mbps
IP (2 main things)
Assigns IP addresses (addresses used by the internet) and breaks data into packets
TCP (2 main things)
(Transmission Control Protocol) establishes network connections between systems and tracks/requests new packets
The 2 addresses for a computer
IP and MAC (media access control)
2 ways to assign an IP address
Static (manual) and DHCP (Dynamic Host Configuration Protocol - creates a pool of IP addresses)
Usually, Static IP addresses are for ______ and DHCP addresses are for ______
Servers; End Users
IP addresses are used to
address network packets
MAC addresses are assigned by the manufacturer of the device and use
12 hexidecimal digits (first 6 identify the manufacturer and the last 6 are a unique identifier assigned by the manufacturer)
3 rules for valid IP address octets
never higher than 255, never start with 127 (loop back), never start with a number greater than 223
IP address that start from 224 - 239 are for
multicast systems
IP address that start from 240 - 255
are for experimental use
Switches connect
all of the devices on a LAN to each other using MAC addresses
Routers manage
traffic to/from the internet and to all of the switches using IP addresses
Firewalls use
rules to allow/block traffic between 2 or more networks
Border Firewalls sit
between LANs and the Internet (most common - protects the overall network)
WiFi uses these items
a radio transceiver, antenna, and wireless access points
WiFi is a
set of rules for interaction for all wireless devices and wireless access points, governed by the IEEE (Institute of Electrical and Electronics Engineers). Different versions of the 802.11 standard
2 major differences between wireless networking versions are
maximum speed and radio frequency range
2.4 GHz networks have
longer range but slower speeds
5 GHz networks have
higher speeds but reduced range (need more wireless access points
802.11
2.4 GHz / 2 Mbps (1997)
802.11b
2.4 GHz / 11 Mbps
802.11a
5.0 GHz / 54 Mbps
802.11g
2.4 GHz / 54 Mbps
802.11n
2.4 or 5 GHz / 600 Mbps (2009) - uses MIMO antenna (Multiple Input/Multiple Output)
802.11ac
5 GHz / 1 (3?) Gbps - uses beam forming antenna scheme
802.11ax
2.4 and 5 GHz (WiFi 6) / 9.6 Gbps
when objects weaken a signal
attenuation
2 basic categories of antennas
Omnidirectional (rubber ducks) -doughnut shaped waves, and directional - increases range by focusing power
beamforming
the access point uses multiple antennas to detect and steer the signal towards the connecting device (virtual directional antenna)
best way to set up a wireless network is to
conduct site survey - measure signal strength, detect electromagnetic interference, and use heat maps to show dead spots
different radio frequencies are known as
channels
the ‘name’ of the wireless network visible to users
SSID (Service Set Identifier)
- broadcasted by default
- disable SSID broadcasting to hide your network
3 methods of wireless authentication
Pre Shared Keys; Enterprise Authentication (server w/username & password); Captive Portals (redirected - must ‘escape’ the portal to access the internet)
WEP is
(Wired Equivalent Privacy) insecure
WPA is
(WiFi Protected Access) insecure (uses TKIP - Temporal Key Integrity Protocol, which changes the encryption key for each packet)
WPA2 is
secure (uses the protocol CCMP - based on AES (advanced encryption standard) )
WPA3
secure (supports CCMP protocol and adds new technology SAE (Simultaneous Authentication of Equals) - a secure key exchange protocol)
The protocol used for web content
HTTP - sever uses this protocol to send content, and the web browser re-assembles the content
The secure protocol for web content
HTTPS - adds encryption (“s” is for “secure”)
used to SEND messages between email servers
SMTP (used if the recipient does not already have an account on the senders server) - use SMTPS (secure)
When you check your email, your email client reaches out to your email server and requests your messages.
This connection can use 3 different protocols
HTTPS (for web based clients - connection takes place over the web, gmail), POP3, and IMAP
POP3
Post Office Protocol (downloads/deletes from server - traditional email clients like Outlook) - older protocol. Used to RECEIVE messages. Secure version is POP3 over TLS
IMAP(S)
Internet Message Access Protocol (messages remain on the server, can access from any device - traditional email clients like Outlook). Used to RECEIVE messages
A subnet mask _______
reveals how many bits in the IP address are used by the network by masking the network portion of the IP address
