Ethernet Designed as baseband system that can be used in multiplexing
CSMA/CD Carrier Sense Multiple Access/ Collision Detection
Unicast Broadcast for a single device
Multicast Broadcast for a specific group or multiple devices
Broadcast Message for everyone to receive and process
Hub Broadcasts packets to every single port
Switch Broadcasts packets to device found on a singular port
Content Addressable Memory (CAM) Is a table that contains the MAC address and port associated to that MAC
Address
Virtual LAN (VLAN) Splitting a switch in which certain ports can only talk to certain ports (Segment
networks within a switch)
Multiprotocol Label Switching (MPLS) A different way of switching packets that can be used on a dedicated line
802.1x Network Access Control that is a layer 2 authentication (Credentialed Question
of 2FA)
A security appliance should be set in place when There is a change in trust level in the network
Protocol is an agreement or rules of engagement for how computer networks
communicate
OSI Protocol Stack (7) Layer 7) Application
Layer 6) Presentation
Layer 5) Session
Layer 4) Transport
Layer 3) Network
Layer 2) Data Link
Layer 1) Physical
Application Layer 7 OSI Stack Browsers, FTP, HTTP, SCP
Presentation Layer 6 OSI Stack Makes data presentable to the application or user (ASCII)
, SANS 401 GSEC Exam
Session Layer 5 OSI Stack Handles the establishment/maintenance of connections between systems
Transport Layer 4 OSI Stack Determines that application the packet should be sent to through port
numbers (Web on 80,443)
Network Layer 3 OSI Stack Moving packets from one network to another network, uses logical addressing
instead of physical addressing
Data Link Layer 2 OSI Stack Takes a packet and frames it suitable for transmission
Physical Layer 1 OSI Stack Network cable, electromagnetic radiation
TCP/IP Protocol Stack (4) Layer 4) Application
Layer 3) Transport (TCP/UDP)
Layer 2) Internet (IP)
Layer 1) Network
Network Address in: 10.1.2.0/24 Subnet 10.1.2.0
Broadcast Address in: 10.1.2.0/24 Subnet 10.1.2.255
Class A CIDR Addressing (Mask, IP Range) N.H.H.H, 255.0.0.0 - 1-127
10.0.0.0/8
16.7 Million IP's
Class B CIDR Addressing (Mask, IP Range) N.N.H.H, 255.255.0.0 - 128-191
172.16.0.0/16
65,536 IP's
Class C CIDR Addressing (Mask, IP Range) N.N.N.H, 255.255.255.0 - 192-223
192.168.1.0/24
256 IP's
Address that broadcasts to current network 255.255.255.255
ARP (Address Resolution Protocol) Required to go from Layer 2 to 3, broadcasts to a network querying for an IP
Address, once found, sends it back to requesting MAC
DNS (Domain Name System) Name to an IP Address (TCP/UDP 53)