< All CompTIA Network+ Notes

MendChrist | CompTIA Network+ | Module 1.5 and 1.6

By: Raul Pop | Related Course: CompTIA Network+ | Published: September 6, 2017 | Modified: September 6, 2017
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NotepadAddress Resolution Protocol

ARP – Address Resolution Protocol


Address resolution protocol is how our computers find out which IP address is associated with which mac address. ARP files are under the layer 3 the data link layer.ARP is how we translate an IP address to a network interface card address.

Who is X tell X

ICMP,IGMP AND ARP dont have protocols associated with it or dont have port numbers associated with them.But they are part of our TCP/IP protocol suite.

NotepadCommunications Protocols:TCP

Communications Protocols

-Set of rules/protocols that dictate how packets are transferred

-Layer 4-Transport Layer


a) TCP-Transmission Control Protocol

-Large packets size (20 bytes header)

-Connection Oriented(Delivery Confirmation)

-Three way hand shake

– SYN-> <- SYN/ACK -> ACK

-Data is a stream


b) UDP-User Datagram Protocol

-Small Packet Size (8 bytes header)

-Connection less

-No error recovery

-Small packets

-Distinct Chucks

-Can be broadcasted




-Transmits from databases

-Google -> IP


b) DHCP-67(server)68(client)-UDP

-Configure IP Address Automatic

-IP,Subnet,DNS,Default Gateway


a) HTTP-80-TCP

-Hyper text transfer protocol

-Web Browsers

-Browsers set a  ”Get” request

-All info in Cleartext


b) HTTPS-443-TCP

-Encrypted HTTP

-Certificate between client/server

-Info not Cleartext

NotepadInternet Control Message Protocol

ICMP + Multicast

-Internet Control Message Protocol

-Deliver Error/Query


-ICMP messages in ping echo requests

-Determine if service is unavailable

-Layer 3 Network



-Internet Group Management Protocol

-Layer 3 Network



-Address Resolution Protocol

-IP => MAC

-Who is x tell x”

-Layer 2 Data Link


ICMP,IGMP AND ARP dont have protocols associated with it or dont have port numbers associated with them.But they are part of our TCP/IP protocol suite.


NotepadPort Communications Endpoints

Ports are communication endpoints for our connections to our computer.

-65,535 ports per net connections

-Allows multiple applications ,protocols connections to our computer.

-Reserved by programs/applications

-Defaults can be changed

-Communications over TCP/UDP

-Transport Layer 4



-File Transfer Protocol

-No encoding/overhead




-Trivial FTP

-Send to multiple clients


c) SFTP:22-TCP

-Encrypts with SSH

-More secure than FTP



-Simple Mail Transfer Protocol

-Email between servers and from (Outlook)

-Outlook->Microsoft-> Yahoo



-Post Office Protocol 3

-Client Download from Server

-Typically copies then deletes


f) IMAP:143-TCP

-Downloads Server->Client

-Keeps copy of message on server

-More config than POP3


a) SIP-5060

-Session Initiation Protocol

-Initiates a session but no data

-Indicates to remote computer to open port for communication


b) RTP-varies depending on customization

-Real Time Protocol

-Stream Video,Audio

-Detects out of Segment Arrival


Used for VOIP connections


a) SNMP-161(Agent)-162(Manage Console)

-Simple Network Management Protocol

-Management of Devices over IP


-Agent is on device and guesseed by Management



-Network Time Protocol

-Devices to Syncronize Time



-Transport Layer Securrity

-succesor to SSL


NotepadTCP/IP Suite

Suite of Protocols for the internet

-TCP-Transmission Control protocol

-verified delivery to endpoint

-one->one communication


-IP-Internet Protocol

-Delivers Packers to Devices

-Maps Logical->Physical


-Routable Protocol


NotepadTCP/IP Suite 2

Protocols which communicates with TCP/IP Suite


1)Layer 2-Data link <=> ARP(Address resolution protocol)

-allows the computes to determine others computers on the networks physical addresses,their mac addresses,and co-relate those with their IP Addresses


2)Layer 3-Network <=> IP,RIP,RIPV2,OSPF,DHCP

3) Layer 4-Transport <=> TCP, UDP

4)Layer 5-Session <=> DNS

5) Layer 7-Application <=> POP3,TFTP,HTTPS,SSH



a) Telnet-23-UDP/TCP

-Remove Terminal Connection

-Unecrypted(in cleartext)

-replaced by SSH


b) SSH-22-TCP

-Encrypted connection between Points

-May work with other protocols


c) RDP-33389-TCP/UDP

-Remove Desktop

-May need to be blocked

< All CompTIA Network+ Notes
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