1. ARP – AddressResolution Protocol: The Address Resolution protocol exists in the Data-LinkLayer of the OSI Model and is used by IPv4. It is used to determine the MAC(Media Access Control) address of a machine when given the IP address.
Thecomputer that wants to send information broadcasts an ARP request whichcontains information about the sender’s IP Address and MAC Address, and thedestination computer’s IP Address. The destination will then know what MACAddress is associated with the sender’s IP Address, and will add this to its ARPtable. It will respond with an ARP reply, where it sends back its IP Addressand MAC address. The original sender will then add this information to it’s ARPtable, at which point both computers have all they need to communicate. If thedestination computer exists on the sender’s subnet, the sender will sendinformation directly to the machine. If it exists on the open internet, it willsend information to the MAC Address of the router.a. http://www.
com/articles/networking-basics-how-arp-works/c. https://www.youtube.com/watch?v=xTOyZ6TWQdM 2. IPv6 –Internet Protocol Version Six: IPv6 is the replacement for IPv4. It solves theproblem of not having enough Internet Protocol addresses for all machines. Theinternet was launched in 1983 and contained 4.3 billion addresses, which at thetime seemed like more than enough.
However, with the advent of mobile internettechnology, if each device had an IPv4 address, all addresses would quickly beexhausted. IPv6 was designed in 1996 and has 128 bits of address space.Therefore, 3.4 x 1038 unique IP addresses can be assigned todevices. If the tech world continued with IPv4, people would eventually not beable to access the internet as they would not have addresses, and the internetwould cease to grow. IPv6, like IPv4, exists in the Network Layer of the OSIModel.a.
com/en-us/HT202236c. 3. IPSec –Internet Protocol Security: IPSec is used to secure communication overnetworks. The original Internet Protocol could not guarantee the authenticity, privacy,or confidentiality of data sent through a network.
Previous to IPSec, securitymeasures were implemented at the application layer. This was not a practical,as such an approach was not general enough and security had to be tailored forspecific applications. IPSec exists at the Network Layer of the OSI Model and allowsone to trust the sender of data by verifying the claim that the sender is thetrue sender, ensures that the data has not been manipulated in any way, andalso that the data was not viewed during transit. IPSec encrypts the trafficbetween two end points.
IPSec works in Transport Mode, which encrypts only thepayload, and Tunnel Mode, which encrypts the entire IP packet.a. https://technet.microsoft.com/en-us/library/cc776369(v=ws.10).
aspxb. http://www.tcpipguide.com/free/t_IPSecurityIPSecProtocols.htmc. https://www.youtube.com/watch?v=mV7BhZx8ch4 4.
BGP – BorderGateway Protocol: BGP is an IP Routing Protocol. It advertises reachabilityinformation between systems. A system tells others that are directly connectedto it which IP Addresses it can reach. Those systems receive that information,along with information about the original sender.
These systems then advertisethat information to other systems they are directly connected to. Those systemsnow know the 2nd to original sender. This gives each system optionson routes to send data through to one of the IP Addresses listed. BGP allowssystems to know which hops are possible, so that they can choose the mostefficient route. BGP exists at the Network Layer in the OSI Model.a. https://www.
metaswitch.com/knowledge-center/reference/what-is-border-gateway-protocol-bgpc. https://www.youtube.com/watch?v=L8dvMwArl88 5. UDP – UserDatagram Protocol: The UDP protocol exists in the Transport Layerof the OSI Model and is used to create connections between Internetapplications.
It is an alternative to TCP (Transmission Control Protocol). UDPis faster, however less reliable. This is because UDP is only 8 bytes in size,compared to TCP which is 24 bytes. Also, TCP has more overhead because of errorcorrection, etc., which make it more reliable, but this also slows it down. UDPis used mainly for live video or audio streams, or VoIP. It excels indelivering real time data.
https://www.lifewire.com/user-datagram-protocol-817976 6. POP3 – PostOffice Protocol version 3: POP3 is a protocol for downloading and storinge-mails using TCP/IP. Once mail is downloaded from the server onto the localmachine, it can be viewed even while offline.
A disadvantage is that after beingdownloaded, the mail is removed from the server. IMAP (Internet Message AccessProtocol) has an advantage over POP3 in that it allows a user to check theiremail from multiple locations. POP3 resides in the Application Layer of the OSIModel.a. https://whatismyipaddress.com/pop3b. https://help.
1and1.com/e-mail-and-office-c37589/1and1-mail-basic-c37590/getting-started-c85087/difference-between-pop3-and-imap-e-mail-accounts-a595515.html 7. HTTPS – HyperText Transfer Protocol Secure: HTTPS is HTTP with a layer of SSL or TLS overtop of it. SSL stands for Secure Sockets Layer while TLS stands for TransportLayer Security. It exists at the Application Layer of the OSI Model. HTTPS is asecure version of HTTP; it encrypts communication between a client and a serverusing public key infrastructure.
The server uses a private key to decrypt thedata sent by the client, and the client uses a public key to encrypt the datain this asymmetric infrastructure. Eavesdropping on communication is stillpossible even when using HTTPS, but an attacker would not be able to decryptthe intercepted data without the server’s private key. This helps to guaranteeserver identity and data privacy.a. https://www.instantssl.com/ssl-certificate-products/https.htmlb.
https://robertheaton.com/2014/03/27/how-does-https-actually-work/c. https://www.youtube.com/watch?v=w0QbnxKRD0w 8.
DHCP – DynamicHost Configuration Protocol: DHCP automatically assigns IP Addresses toclients, ensuring that no two clients have the same address which would causean IP Conflict. It exists in the Application Layer of the OSI Model. For DHCPto work, machines on the network must run a DHCP client, and the network musthave a DHCP server. When a new client attempts to join a network, it finds theDHCP server by broadcasting to all machines on the network. The DHCP server repliesby offering an IP Address to all machines on the network, because it does not knowwhere the requesting client is as its IP Address is not assigned yet. The clientwill then reply by broadcasting to all machines on the network that it accepts theIP Address given by the DHCP server. This is a DHCP ACK, DHCP acknowledgement. TheDHCP Server then broadcasts to all machines that the client can go ahead and usethat address for a certain amount of time.
The time limit is used so that IP Addressescan be recycled.a. https://www.youtube.com/watch?v=RUZohsAxPxQb. https://technet.
dummies.com/programming/certification/installing-and-configuring-dhcp/ 9. SLIP – Serial LineInternet Protocol: SLIP generates a character sequence that organizes IP packetson a serial line. It does little else, which makes it easy to implement. It is outdatedand replaced by PPP (Point to Point Protocol), and is used to connect machines acrossa modem line or cable connection. It is a protocol found at the Data-Link Layerof the OSI Modela. https://tools.
http://www.webhart.net/garry/html/TC0201.html 10. ICMP – InternetControl Message Protocol: ICMP protocol sends control messages that relayinformation about problems in communication, errors reports, and hop routing. Itexists in the Transport Layer of the OSI Model. The ICMP header is composied ofType, which is 8 bits, Code which is 8 bits, a checksum of 16 bits, and a variablelength of data.
ICMP follows the MAC Header and IP Header of a packet.