Disclamer

These are my personal notes and not a complete course

OSI Layers

IPv4 Addressing

Human 203.0.113.16
Dot Decimal Notation
Machine 11001011.00000000.01110001.00010000
Binary Notation

  • Oktett 1 und 4 beginns  with 1 und ends with 254
  • Oktett 2 and 3 beginn with 0 and end with 255

Aufbau eines 8 Bit Bytes

128 64 32 16 8 4 2 1
0 0 0 1 0 0 0 0

Network Segmentation

APIPA

APIPA is short for Automatic Private IP Addressing
169.254.0.1 through 169.254.255.254

Classes

Class A
0.  0.  0.  0 = 00000000.00000000.00000000.00000000
127.255.255.255 = 01111111.11111111.11111111.11111111
                  0nnnnnnn.HHHHHHHH.HHHHHHHH.HHHHHHHH

Class B
128.  0.  0.  0 = 10000000.00000000.00000000.00000000
191.255.255.255 = 10111111.11111111.11111111.11111111
                  10nnnnnn.nnnnnnnn.HHHHHHHH.HHHHHHHH

Class C
192.  0.  0.  0 = 11000000.00000000.00000000.00000000
223.255.255.255 = 11011111.11111111.11111111.11111111
                  110nnnnn.nnnnnnnn.nnnnnnnn.HHHHHHHH

Port Numbers

Well-known ports range from 0 through 1023.
Registered ports are 1024 to 49151.
Dynamic ports (also called private ports) are 49152 to 65535.

Network Protokolls

IP
TCP
PPP
DNS
UDP
ARP
IGMP
ICMP
SNMP
BOOTP/DHCP

Potokoll Ports

FTP (TCP/UDP/20 and 21)
SSH (TCP/22)
SFTP (TCP/22)
Telnet (TCP/23)
SMTP (TCP/25)
DNS (TCP/UDP 53)
BOOTP (UDP 67 and 68)
TFTP (UDP/69)
HTTP (TCP/80)
POP3 (TCP/110)
NNTP (TCP/119)
RCP (UDP/TCP 135)
IMAP4 (TCP/143)
SNMP (TCP 161)
HTTPS (TCP/443)
SMB (TCP/445)
Syslog (TCP/UDP 513)
MS-SQL (TCP/1433)
RADIUS (1645, 1646, 1812,1813,1814)
RDP (TCP/3389)
IRC (TCP/6667)

Signal Types

  • Analog
  • Digital
  • Asynchronous
  • Synchronous
  • Broadband (Channel based separation of the spectrum)
  • Baseband (Use the entrire transmission spectrium)

Cabeling

  • Cable Categories (Cat 1 through 7)

Media Access Methods

  • CSMA/CD - Carrier Sense Multiple Access / Collision Detection
  • CSMA/CA - Carrier Sense Multiple Access/Collision Avoidance
  • Token passing
  • Polling

Communicating within a Network

  • Unicast (One to One)
  • Multicast (One to Group)
  • Broadcast (One to Everyone)

Network Protocols and Services

  • ARP (IP to MAC)
  • RARP (MAC to IP)
  • DHCP (DORA Discover, Offer, Request, Acknowledgment / Negotiation is Broadcast based)
  • ICMP
    • Type 0 Echo Reply (Ping Reply, used with Type 8, Ping Request)
    • Type 3 Destination Unreachable
    • Type 4 Source Quench
    • Type 5 Redirect
    • Type 8 Echo
    • Type 9 Route Advertisement
    • Type 30 Traceroute
  • SNMP (Version 3 includes Encryption, Management Protocol)
  • DNS

  • E-Mail

Network Addresse Translation

  • NAT
    • Static Mapping
    • Dynamic Mapping
    • Port Address Translation (PAT) 
    • Routing Strategies
      • Distance Vector (Hopps between Endpoints)
      • Link State (Active communication of link conditions) 
    • Routing Protocols
      • Interior
        • RIP (v1, v2) (Distance Vector)
        • IGRP (Distance Vector)
        • EIGRP (Distance Vector)
        • OSPF (Link State)
        • IS-IS
      • Exterior
        • BGP (Link State and Distance Vector)
        • EGP (Outdated)
      • Link Flapping (Fluctuation of Link State)
      • Black Hole (When a Link state does not recieve an update)

Firewall

  • Firewall
    • Hardware
    • Software
  • Firewall Generations
    • 1st - Paket Filers
    • 2nd - Application Layer (Proxy)
    • 3rd - Statefull Packet Filering (Looks at all layers of the OSI Model)
    • 4rh - Dynamic Packet Filtering (Able to see patterns, dynamic changing of rules)
    • 5th - Kernel Filtering (Dynamically create virtual stack for analysis in real time)

Cloud Computing

  • Software as a Service (SaaS)
  • Plattform as a Service (PaaS)
  • Infrastructure as a Service (IaaS)

  • Virtual Private LAN Service (VPLS) (Connecting two or more endpoints together)
  • Asynchronous Transfer Mode (ATM) (Used a fixed cell size to transmit data)

Multiplexing

  • Multiplexing Types
    • Statistical Time Division
    • Frequency Division
    • Wave Division


Statistical Time Division


Frequency Division


Wave Division

WAN Technologies

  • CSU/DSU
    • Channel Service Unit
    • Data Service Unit
    • Bridges the division between LAN and WAN
  • Packet Switches
    • x. 25
    • Frame-relay
  • Circuit Switches
    • ISDN
  • Virtual Circuits
    • Permanent Virtual Circuits
    • Switch Virtual Circuits
  • Virtual Private Network (VPN)
    • Point-to-Point Tunneling Protocol (PPTP) 
      • Data-Link Layer
      • Transmits only on IP networks
    • Layer 2 Tunneling Protocol (L2TP)
      • Extends beyond IP based networks
      • Uses IPSec for Securiy
      • Combined PPTP with L2F (Layer-2 Forwarding)
    • Internet Protocol Security (IPsec)
      • Tunnel-Mode for LAN to LAN over WAN
      • Transfer-Mode inside a LAN
      • Layer 3 of OSI
    • Secure Socket Layer (SSL)
      • Layer 4 of OSI
      • Used primarily with web traffic

Authentication Protocols

  • Password Authentication Protocol (PAP)
    • Password is send in clear
  • Microsoft CHAP (MS-CHAP)
    • Microsoft proprietary
    • MS-CHAPv2
  • Extensible Authentication Protocol (EAM)
    • Lightweight EAP (LEAP)
    • EAP-LTS
    • EAP-IKE2

Wireless

Spread Spectrum Technology

Multiplexing Technology

Wireless Components

  • Access Point
  • SSID
  • Security
    • Wireless Equivalent Protocol (WEP)
      • 802.11
    • Temporal Key Integrity Protocol (TKIP)
    • 802.1x
    • 802.11i
    • Wi-Fi Protectet Access (WPA)
      • 802.1x or PSK for access control
      • Uses EAP for authentication
      • Uses TKIP (RC4) for encryption
      • Uses MIC for integrity
    • WPA2
      • 802.1x or PSK for access control
      • Uses EAP for authentication
      • Uses AES Countermode for encryption
      • Uses AES CBC-MAC for integrity
    • Wireless Standards
      • 802.11a
        • 5GHz
        • 54Mbps
        • OFDM
      • 802.11b
        • 2.4GHz
        • 11Mbps
        • OSSS
      • 802.11g
        • 2.4GHz
        • 54Mbps
        • OFDM
      • 802.11n
        • 5GHz
        • 100Mbps
        • MIMO
      • 802.15
        • Wireless Personal Area Network (WPAN)
        • Bluetooth
          • Bluesnarfing (unauthorized access of information from a wireless device through a Bluetooth connection)
          • Bluejacking (sending of unsolicited messages over Bluetooth)
      • 802.16
        • Wireless Metropolitan Area Network (WMAN)
        • WiMAX

Mobile Wireless

  • Multiple Access Technologies
    • Frequency Division Multiples Access (FDMA)
      • Sliced by separation
    • Time Division Multiple Access (TDMA)
      • Sliced by time
    • Code Division Multiple Access (CDMA)
      • Assign code to every voice call
    • Orthogonal Frequency Division Multiple Access (OFDMA)
      • Combines FDMA and TDMA
  • Mobile Generations
    • 1G
      • First Generation
      • Analog Only
      • FDMA
    • 2G
      • Cirquit Switched
      • TDMA
    • 3G
      • Packet Switched
      • CDMA
    • 4G
      • Packet Switched
      • OFDMA