Networking :3 Flashcards
This module makes me wanna kms :>
TCP Three-Way Handshake explanation
Establishes that destination device is present on network
Verifies the destination device has an active service and is accepting requests on the destination port number
Informs destination device that source client intends to establish a communication session on that port number.
Definition of 3 way handshake
establishes a connection between a client and server
DHCP
Dynamic Host Configuration Protocol
Automatically assigns IP addresses
DHCP ATTACKS >:(
DHCP SPOOFING
DHCP Starvation :o
TCP
Transmission Control Protocol
Reliable, connection-oriented transport layer protocol.
UDP
User Datagram Protocol
Unreliable, connectionless transport layer protocol.
POP :o
Post Office Protocol
Protocol for receiving emails
(TCP)
IMAP
Internet Message Access Protocol
Protocol for accessing and managing emails on a server
(TCP)
FTP
File Transfer Protocol
Protocol for transferring files
(TCP)
TFTP
Trivial File Transfer Protocol
Simplified FTP without authentication
(UDP)
HTTP
HyperText Transfer Protocol
Protocol for web browsing
(TCP) :3
HTTPS
HyperText Transfer Protocol
Secure version of HTTP using SSL/TLS
(TCP, UDP)
DNS
Domain Name System
Resolves domain names to IP addresses
(TCP, UCP)
SMTP
Simple Mail Transport Protocol
Protocol for sending emails
(TCP)
Broadcast Domain
Devices use broadcasts in an ethernet LAN to locate: other devices like ARP, services like DHCP
Collision Domain
A network segment where network devices contend for access to communication medium and collisions can occur.
Telnet
Teletype Network
provides access to virtual terminals of remote systems on local area networks or the Internet
Telnet transfers the data in plain text
SSH
Secure Shell
Secure remote login protocol
Transfers data that is encrypted
Firewall Techniques
Packet Filtering, application filtering, URL filtering, Stateful Packet Inspection (SPI)
Packet Filtering
Prevents/allows access based on IP or MAC addresses
Application Filtering
Prevents/allows by specific application types based on port numbers
URL Filtering
Prevents/allows access to websites based on specific URLs or keywords
SPI
Stateful Packet Inspection
Incoming packets must be legitimate responses to requests from external hosts
Viruses
copies itself and spreads by attaching to other files or programs
WORMS!
Don’t need a host, self-replicates, spreads across networks and systems independently
Trojan Horse (neigh)
Disguises itself tricking users into executing it. Usually create a backdoor
Switch Forwarding Method?
Cut-through Switching
Switch buffers just enough of the frame to read destination MAC addresses so it can determine to which port to forward the data
Two variants:
Fast-Forward
Fragment-Free
ARP :o
Address Resolution Protocol
Maps IP addresses to MAC addresses
-device will search its ARP table/ARP cache to find IPv4 address and its corresponding MAC address
If on different device search ARP table for IPv4 address of default gateway
ARP performance issue
excessive broadcasts can lead to network congestion
ARP security issue
ARP Spoofing: send false ARP messages
Transport Layer
Responsible for establishing a temporary communication session between 2 applications and delivering data between them
PDU: Segment
Addressing Type: Port Numbers
Protocol: TCP, UDP
Network Layer
Responsible for logical addressing, routing and forwarding
PDU: Packet
Addressing Type: IP addresses
Protocol: IPV4, IPV6
Data Link Layer
Handles physical addressing, framing, error detection
PDU: Frame
Addressing Type: MAC address
Protocol: Ethernet
Application Layer
Used to exchange data between programs running on the source and destination hosts
PDU: Data
Protocol: DHCP, DNS,
Physical Layer
Provides the means to transport the bits that make up a data link layer frame across the network media
PDU: Bits
Protocol: uh :3
Types of threats
Info theft
Data loss and manipulation
Identity theft
Disruption of service
Bandwidth
Capacity of a medium to carry data
throughput
measure of the transfer of bits across the media over a period of time
Encapsulation :>
Data is divided into segments
TCP segment is encapsulated in IP Packet
IP Packet is encapsulated in Ethernet Frame
NEVER BACK DOWN NEVER WHAT?
NEVER GIVE UP! :-)
