ADDRESS RESOLUTION PROTOCOL (ARP) VS INTERNET CONTROL MESSAGE PROTOCOL (ICMP):

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FOR MORE REFERENCES:

◙ - ➤  For More About - > DESCRIPTION OF EACH PROTOCOLS :

◙ - ➤  For More About - > BASIC COLLECTION OF NETWORKING CONCEPTS:

◙ - ➤  For More About - > BASIC NETWORKING QUESTIONS AND ANSWER:

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NETWORK INTERFACE LAYER / LINK LAYER / DATA LINK LAYER :

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NETWORK INTERFACE LAYER:

The Network Interface Layer (Also Called The Network Access Layer) Is Responsible For Placing TCP/IP Packets On The Network Medium And Receiving TCP/IP Packets Off The Network Medium. The Network Interface Layer Encompasses The Data Link And Physical Layers Of The OSI Model.

LINK LAYER:

The Link Layer In The TCP/IP Model Is A Descriptive Realm Of Networking Protocols That Operate Only On The Local Network Segment (Link) That A Host Is Connected To. Such Protocol Packets Are Not Routed To Other Networks. In Computer Networking, The Link Layer Is The Lowest Layer In The Internet Protocol Suite, Commonly Known As TCP/IP, The Networking Architecture Of The Internet.

It Is Described In RFC 1122 And RFC 1123. The Link Layer Is The Group Of Methods And Communications Protocols That Only Operate On The Link That A Host Is Physically Connected To. The Link Is The Physical And Logical Network Component Used To Interconnect Hosts Or Nodes In The Network And A Link Protocol Is A Suite Of Methods And Standards That Operate Only Between Adjacent Network Nodes Of A Local Area Network Segment Or A Wide Area Network Connection. Despite The Different Semantics Of Layering In TCP/IP And OSI, The Link Layer Is Sometimes Described As A Combination Of The Data Link Layer (Layer 2) And The Physical Layer (Layer 1) In The OSI Model.

DATA LINK LAYER :

In The Seven-Layer OSI Model Of Computer Networking, The Data Link Layer Is Layer 2. In TCP/IP Reference Model, It Corresponds To, Or Is Part Of The Link Layer. The Data Link Layer Is The Protocol Layer That Transfers Data Between Adjacent Network Nodes In A Wide Area Network Or Between Nodes On The Same Local Area Network Segment.

The Data Link Layer Is Described In More Detail With Media Access Control (MAC) And Logical Link Control (LLC) Sublayers; This Means That The IEEE 802.2 LLC Protocol Can Be Used With All Of The IEEE 802 MAC Layers, Such As Ethernet, Token Ring, IEEE 802.11, Etc.

◙ - ➤  For More About - > FUNCTION OF OSI LAYERS:

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ARP VS IGRP

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ADDRESS RESOLUTION PROTOCOL (ARP):

ARP Is Enables The Packaging Of IP Data Into Ethernet Packages. It Is The System And Messaging Protocol That Is Used To Find The Ethernet (Hardware) Address From A Specific IP Number. Without This Protocol, The Ethernet Package Could Not Be Generated From The IP Ackage, Because The Ethernet Address Could Not Be Determined.

The ADDRESS RESOLUTION PROTOCOL (ARP) Is A Telecommunication Protocol Used For Resolution Of Network Layer Addresses Into Link Layer Addresses, A Critical Function In Multiple-Access Networks. ARP Was Defined By RFC 826 In 1982. ARP Has Been Implemented With Many Combinations Of Network And Data Link Layer Technologies. Short For Address Resolution Protocol, A Network Layer Protocol Used To Convert An IP Address Into A Physical Address, Such As An Ethernet Address. ARP Assists IP In Directing Datagrams To The Appropriate Receiving Host By Mapping Ethernet Addresses (48 Bits Long) To Known IP Addresses (32 Bits Long).

ARP Converts Between IP Addresses (Network Layer) and MAC Addresses (Data Link Layer). ARP Itself Is A Layer 2 Protocol, But It Maps Layer 2 Addresses To Corresponding Layer 3 Addresses. The Address Resolution Protocol (ARP) Conceptually Exists Between The Data Link And Internet Layers.

The REVERSE ADDRESS RESOLUTION PROTOCOL (RARP) Converts A Hardware Address To An IP Address. ARP Packets Include A Function Code Such As ARP Request, ARP Reply, RARP Request, And RARP Reply. ARP And RARP Requests Are Broadcast Packets That Include The Query Information. INVERSE ADDRESS RESOLUTION PROTOCOL (Inverse ARP Or INARP) Is Used To Obtain Network Layer Addresses (For Example, IP Addresses) Of Other Nodes From Data Link Layer (Layer 2) Addresses. It Is Primarily Used In Frame Relay (DLCI) And ATM Networks, In Which Layer 2 Addresses Of Virtual Circuits Are Sometimes Obtained From Layer 2 Signaling, And The Corresponding Layer 3 Addresses Must Be Available Before Those Virtual Circuits Can Be Used.

INTERNET CONTROL MESSAGE PROTOCOL (ICMP):

ICMP Is The Protocol Responsible For Detecting Network Error Conditions And Reporting On Them. The Internet Control Message Protocol (ICMP) Is One Of The Main Protocols Of The Internet Protocol Suite. It Is Used By Network Devices.

It Is Assigned Protocol Number 1. ICMP Differs From Transport Protocols Such As TCP And UDP In That It Is Not Typically Used To Exchange Data Between Systems.

◙ - ➤  For More About - > TCP VS UDP:

ARP Is How End Devices On The Same Network Segment Learn The Layer 2 MAC Addresses For One Another. ICMP Is Used For A Wide Variety Of Different Network Control And Management Function.

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IF ARP IS - DATA LINK LAYER ADDRESSING / NETWORK LAYER ADDRESSING?

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If ARP Is - DATA LINK LAYER ADDRESSING / NETWORK LAYER ADDRESSING?

ARP (ADDRESS RESOLUTION PROTOCOL) Is A Communications Protocol Used For Converting Between IP Addresses And Physical Addresses (MAC Address). ARP Itself Is A Layer 2 Protocols, But It Maps Layer 2 Addresses To Corresponding Layer 3 Addresses.

It Is Important To Realize That ARP Is Only Used On LANs (Local Area Networks). Originally, All Computers Were Directly Connected To The Internet, So All Routing Was Based On IP Addresses.

Before We Begin The Discussion Of ARP, An Understanding Of The Difference Between DLC (Physical) Layer Addresses And Network Layer Addresses Is Required. We Discussed, In The PREFACE To The Compendium, Why We Use The Term "DLC" (Data Link Control) To Refer To The Data Link Layer Address; The Network Interface Card Address. An Entity On A Network Generally Has Two Addresses, The DLC (Data Link Control) Address, Refers To The Actual Burned-In Address That Is On The Individual NIC In A Station. DLC Addresses Are Used In The Lowest Layer Of Communications And Get The Message From NIC To NIC. The Second Address, The Network Layer Address, Is Usually Configured In The Protocol Stack Software, And Is Used To Convey The Message From Logical Endpoint To Logical Endpoint. Some Protocol Stacks Do Not Implement A Network Layer. Stations Using These Protocols Address Solely At The Data Link Layer.

Ethernet And Token-Ring Cards Only Know How To Recognize The DLC Addresses, Therefore, Any Communicator On A Network Must Be Able To Specify The DLC Address Of Both Itself And The Destination Of Its Messages.

FOR EXAMPLE: A Message Traveling From One Logical Endpoint To Another Logical Endpoint (Station To Station, For Example) Might In Reality Pass Through Several Different NICs Before Reaching Its Destination. In The TCP/IP World, A Packet Destined For A Station That Is Several Gateways Away Would Be Addressed To The Destination Station At The Network Layer, But At The DLC Layer Would First Be Addressed To The First Gateway, Then The Second, Then The Third, Etc.

Until The Final Gateway Addressed The Packet To The Destination. Here, We See That At The Network Layer The Packet Is Addressed To The Logical Endpoint Of The Conversation (The Receiving Station), But At The DLC Layer, The Packet Had To Pass Through Several NICs, So The DLC Address Changed.

In Order To Associate DLC Addresses With Network Layer IP Addresses, A TCP/IP Station Maintains A Record Called An ARP Cache. The ARP Cache Contains Mappings Of DLC Addresses To IP Addresses, And When A Station Wants To Send A Message To An IP Address, It Looks For The IP Address In Its ARP Cache, Finds The Associated DLC Address, And Can Then Properly Address The Message.

The Address Resolution Protocol Comes Into Play When A Station Wants To Communicate With A Certain IP Address, But Does Not Have An Entry For The IP Address In Its ARP Cache. A Station In This Position Sends Out An ARP Frame Addressed To The DLC Broadcast, So That All IP Stations On The Network Will Receive The Frame.

The Address Resolution Protocol (ARP) Is A Request And Reply Protocol That Runs Encapsulated By The Line Protocol. It Is Communicated Within The Boundaries Of A Single Network, Never Routed Across Internetwork Nodes.

This Property Places ARP Into The Link Layer Of The Internet Protocol Suite While In The Open Systems Interconnection (OSI) Model, It Is Often Described As Residing Between Layers 2 And 3, Being Encapsulated By Layer 2 Protocols. However, ARP Was Not Developed In The OSI Framework.

For A Device To Take Part In A Layer 3 Protocol Such As IP, It Has To Be Able To Send And Receive These Packets Through A Layer 2 Medium.

ARP Packets Are Not Routable (The Packets Will Not Go Beyond Your Router) Nor Do They Have IP Headers. ARP Is A Broadcast Frame That Is Sent On A Layer 2 Segment. ARP Was First Defined In RFC 826. It Is Evident From The Content That Discovering The Mac Address Of A Target IP-Address Is Only Useful, For Packet Delivery, Within A Single Local Broadcast Domain. Since ARP Is A Non-Routable Protocol,

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CONCLUSION:

The Goal Of This Article Is To Give An Easy Way To Understand The “Address Resolution Protocol (ARP) VS Internet Control Message Protocol (ICMP)” And Also We Hope This Guide Will Help Every Beginner Who Are Going To Start Cisco Lab Practice Without Any Doubts. Some Topics That You Might Want To Pursue On Your Own That We Did Not Cover In This Article Are Listed Here!

Hands - On Experience Is An Invaluable Part Of Preparing For The Lab Exam And Never Pass Up An Opportunity To Configure Or Troubleshoot A Router ( If You Have Access To Lab Facilities, Take Full Advantage Of Them) There Is No Replacement For The Experience You Can Gain From Working In A Lab, Where You Can Configure Whatever You Want To Configure And Introduce Whatever Problems You Want To Introduce, Without Risk Of Disrupting A Production Network. Thank You And Best Of Luck

This Article Written Author By: Mr. Premakumar Thevathasan - CCNA And CCNP (Routing & Switching), MCSE, MCSA, MCSA - MSG, CIW Security Analyst, CompTIA Certified A+ And Etc.

WARNING AND DISCLAIMER:

Routers Direct And Control Much Of The Data Flowing Across Computer Networks. This Guide Provides Technical Guidance Intended To Help All Network Students, Network Administrators And Security Officers Improve Of Their Demonstrated Ability To Achieve Specific objectives Within Set Timeframes.

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It Is Offered In The Hopes Of Helping Others, But You Use It At Your Own Risk. The Author Will Not Be Liable For Any Special, Incidental, Consequential Or Indirect Any Damages Due To Loss Of Data Or Any Other Reason That Occur As A Result Of Using This Document. But No Warranty Or Fitness Is Implied. The Information Provided Is On An "As Is" Basic. All Use Is Completely At Your Own Risk.

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