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Group 10 - Coggle Diagram
Group 10
DNS and DHCP
Domain names convert the numeric address into a simple, recognizable name.
The DNS protocol defines an automated service that matches resource names with the required numeric network address.
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When a client makes a query, the server’s DNS process first looks at its own records to resolve the name.
If unable to resolve, it contacts other servers to resolve the name.
The server temporarily stores the numbered address in the event that the same name is requested again.
The ipconfig /displaydns command displays all of the cached DNS entries on a Windows PC.
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DNS Hierarchy
The nslookup Command
Nslookup - a utility that allows a user to manually query the name servers to resolve a given host.
Can also be used to troubleshoot name resolution issues and to verify the current status of the name servers.
DHCP Operation
web and email protocols
web
- HTTP and HTTPS
HTTP is a request/response
protocol.
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EMAIL
Email clients communicate with mail servers to send and receive email.
Mail servers communicate with other mail servers to transport messages from one domain to another.
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Establishing a Session
◦ Connection-oriented protocol
◦ Ensures the application is ready to receive the data
◦ Negotiate the amount of traffic that can be forwarded at a given time
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Responsible for establishing a
temporary communication session between two
applications and delivering data between them
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Tracking the Conversation - Tracks each individual conversation flowing between
a source and a destination application.
Segmentation - Divides the
data into segments that are easier to manage and
transport. Header used for reassembly is used for tracking
Identifying the Application - Ensures that even with multiple applications running
on a device, all applications receive the correct data via
port numbers.
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Source Port
◦ Originating application port
that is dynamically generated
by sending device Example: Each separate HTTP
conversation is tracked based on the source ports.
Destination Port
◦ Tell the destination what service is being requested
◦ Example: Port 80 web services
are being requested
Non – guaranteed UDP transmission are best suited for common applications
- used in message transport or transfer. This is not connection based which means that one program can send a load of packets to another and that would be the end of the relationship.
How the functions of the application layer, session layer, and presentation layer work together to provide network service to end user applications
- The presentation layer is responsible for formatting and converting data and ensuring that the data is presentable for one application through the network to another application. The session layer is responsible for coordinating communication interactions between applications