OSI Model

Address Formats

Mac Adresses - Media Access Control

• OSI Layer 2 Addesses
• Physical address of the network adapter card
• MAC addresses have 12 hexadecimal characters so it's 12x4(bits) which is 48(bits). Divide that by 8(bits) which leaves you with 6(bytes).

Six bytes, usually represented in hexadecimal

• First three bytes are assigned by the IEEE to the manufacturer
• OUI - Organizationally Unique Identifer
• Last three bytes are usually assigned sequentially
• Duplicates are rare

Internet Protocol V 4

• OSI Layer 3 Address
• Since One byte is 8bits, the maximum decimal value for each byte is 255

Internet Protocol V6
OSI Layer 3 Address

• Groups of zeros can be abbereviated with a double colon ::
• Only one abbreviation allowed per address
• Leading zeros are optional
• Your DNS will become very important for the long ipv6 address

Common UDP And TCP Ports

TCP and UDP ports can be any number between 0 and 65,535

-+Most servers (Services) Use non-ephemeral port numbers (not always a case, just a number)
-+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


IPV4 With TCP/UDP

• Server ip address, server application port number

• Client ip addres, client port number

Non-Ephemeral ports - Permanent port numbers

• usually on a server or service

Ephemeral Ports - Temporary port numbers

• Determined in real-time by the client workstation

TCP Ports
FTP - File Transfer Protocol tcp/20 (data), tcp/21 (control)
SSH - Secure Shell tcp/23
Telnet - tcp/23
SMTP - Simple Mail Transfer Protocol tcp/25
DNS - Domain Name Services tcp/53 (Zone Transfers)
HTTP - Hyper Text Transfer Protocol tcp/80
Pop3 - Post Office Protocol Version 3 tcp/110
IMAP4 - Internet Message Access Protocol V4 tcp/143
HTTPS - Hypertext Transfer Protocol Secure tcp/443

UDP Ports 
DNS - Domain Name Services udp/53 (Queries)
BOOTP / DHCP - Bootstrap Protocol / Dynamic Host Configuration Protocol udp/67
TFTP - Trivial File Transfer Protocol udp/69
NTP - Network Time Protocol udp/123
SNMP - Simple Network Management Protocol udp/161


All Information was learned from Professor Messer

Application Layer Protocols (TCP/IP Suite)

Application Layer TCP/IP

Management Porotocols

• BootP, DNS, DNS, SNMP, NTP

Remote Communcations Protocols

• Telnet, SSH

File Transfer Protocols

• FTP, TFTP

Mail Application  Protocols

• SMTP, Pop3, IMAP4

Browser Protocols

• HTTP, HTTPS, TLS/SSL

Voice Over IP (VOIP) Protocols

• SIP, RTP

BootP - Bootstrap Protocol

• Automates the ip address configuration process
• Replaced by DHCP Dynamic Host Configuration Protocol (A dynamic version of BootP)

DNS - Domain Name Services

• Converts domain names to IP Addresses (so you don't have to remember IP Address of websites)

NTP - Network Time Protocol

SNMP

• Automatically synchronizes clocks

SNMP - Simple Network Management Protocol
Gather Statistics from network devices

• V1 - Structured tables, In-The-Clear.
• V2 - Data Type Enhancements, bulk transfers, still in-the clear (not encrypted)
• V3 Message integrity, Authentication, Encryption

Telnet - Telecommunication Network

• Login to devices remotely
• Unencrypted communication, not the best choice on production systems

SSH - Secure Shell

• Looks and acts the same as telnet
• Encrypted communication link

FTP - File Transfer Protocol

• Transfers files between systems
• Authenticats with a username and password
• Full-featured functionality (list, add, delete, etc.)

TFTP - Trivial File Transfer Protocol

• Very simple file transfer application
• Read and write files
• No authentication
• Not used on production systems

SMTP - Simple Mail Transfer Protocol

• Used most often for sending mail
• Transferring between mail servers

POP3 - Post Office Protocol Version 3

• Receive mail
• Designed for intermittent connectivity

IMAP4 - Internet Message Access Protocol V4

• Another mail client protocol (Pop3 more popular)
• Flexibility in connectivity
• Keeps "State" - Read, Replied, Deleted (see mail as you left it)
• More functional than POP3

HTTP - Hypertext Transfer Protocol

• Internet Access

HTTPS - Hypertext Transfer Protocol Secure

• Same as HTTP with an extra layer of encryption through TLS/SSL

TLS/SSL - Transport Layer Security and Secure Sockets Layer

• SSL was created by netscape
• TLS is the updated IETF (Internet Engineering Task Force) Version of SSL

SIP - Session initiation Protocol (behind the scenes)

• VOIP signaling Protocol
• Builds and tears-down media calls
• Makes sure the call continues

RTP - Real-Time Transport Protocol

• Carries the media stream (Voice and video data)

All Information was learned from Professor Messer

TCP/IP Protocol Suite

TCP/IP Protocol Suite, AKA Internet Protocol Suite
Similar to OSI model but more compatible with TCP/IP

Consists of 4 layers

• Application, TCP, Bootp, TFTP, DNS, HTTP(S), TLS/SSL, VOIP(Sir,Rtp), SSH, Pop3, IMAP4, NTP, Telnet, SMTP, SNMP
• Transport, TCP UDP
• Internet, IPV4, IPV6, ICMP, IGMP
• Link, ARP

 The router only looks up to Internet layer before passing on data to another network

ARP - Address Resolution Protocol
CMD Command for ARP: arp -a
IP Address to MAC address resolution and vice versa.

IPV4

• Most common protocol at internet layer
• 32-bit 4byte addresses
• IP only cares about moving data from one source to another
• Addresses shown in Dot-Decimal (192.168.1.1)

IPV6

• Next Generation IP
• More Addresses
• Improves routing, security, efficiency and more
• Addresses shown in Hex Digits (2002:4bg6:5dn5:0000:0000:0000:4bfu:5dg6)

ICMP - Internet Control Message Protocol

• Sends management messages between systems
• Echo Request, Echo Reply (Ping)
• Tells us when a host is unreachable

IGMP -  Internet Group Management Protocol

• Manages membership of multicast groups
• Improves efficiency and bandwidth usage

TCP - Transmission Control Protocol

• Connection-Oriented
• Reliable delivery
• Can manage out of order messages or retransmissions
• Loads/Unloads data from IP

UDP - User Datagram Protocol

• Connectionless
• UDP does not care if the host has received data or not
• Faster than TCP
• Unreliable
• No reordering of data or retransmissions

All Information was learned from Professor Messer