Term
| What are the Standards and Protocols of the Internet Architecture? |
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Definition
- Facilitate interoperability
- Preferably open standards
- A key to internet growth
- 'Everything over IP'
- The Internet Protocol
- IP is the 'Internet Glue'
- Currently using IPv4 but will migrate to IPv6
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Term
| What are the layers of the TCP/IP layered model? |
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Definition
- Application layer
- APIs, Socket Libraries, Java RMI, etc.
- Transport layer
- TCP(Connection oriented), UDP (Connecitonless)
- Network Layer
- Data link Layer
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Term
| What is the function of the TCP/IP Layered model? |
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Definition
| Layered model provides abstraction. Applications shouldn't have to go into too much trouble about detailed and complex data link technology |
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Term
| What are the basic principles of networks of networks (Eg. the internet)? |
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Definition
- Need interoperability across the different access and core network technologies
- eg. an ADSL link to an Ethernet home network
- Connecting edge networks
- Need protocols to allow data to be sent(routed) between such networks
- The use of common IP layer
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Term
| What allows interoperability across the whole internet? |
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Definition
| The use of common IP layer and addressing scheme |
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Term
| What are the basic principles of Routing? |
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Definition
- Provides connectivity within/between sites (eg. An ADSL router for your home network)
- A router may serve a host subnet at the edge or simply provide connectivity to other routers
- Routing protocols are used to build routing tables
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Term
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Definition
| The process of determining the path from client to server |
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Term
| What is the most common use of Network Routing between sites? |
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Definition
| The BGP routing (Border Gateway Protocol) |
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Term
| What is the BGP (Border Gateway Protocol) routing and what does it consist of? |
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Definition
| The BGP is a protocol for exchanging routing information between gateway hosts (each with its own router) in a network of autonomous systems. It consists of a routing table which contains a list of known routers, the addresses they can reach, and a cost metric associated with the path to each router so that the best available route is chosen. |
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Term
| What is an Autonomous System (AS)? |
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Definition
| Either a single network or a group of networks that are controlled by a common network administrator on belalf of a single administrative entity (Such as a university or a simple website) |
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Term
| What is a gateway (networks)? |
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Definition
| A network point that acts as an entrance to another network. |
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Term
| Provide an example of a BGP (Border gateway protocol) |
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Definition
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Term
What basic information does a device require to be able to operate in a network of networks? |
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Definition
- Information is typically supplied by DHCP server
- For IPv4 this will include:
- An IP address, e.g. 152.78.64.33
- A default router address, e.g. 152.78.64.1
- Knowledge of size of local network or 'subnet'
- IP addressess of DNS resolvers
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Term
| What are the principles of Naming and Addressing? |
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Definition
- There is a need to be able to name/address devices and network components at different layers
- A user running an application should only need to be exposed to the upper application layer
- Users should not be aware of addressing at lower layers
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Term
| What are the addressing schemes through layers? |
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Definition
- Domain names
- Port Numbers
- IP addresses
- Ethernet addresses
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Term
| Give an example of addressing schemes through layers |
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Definition
- Application: Domain name, www.bbc.co.uk
- Transport: port number, 80 (http/web)
- Internet: 32-bit IPv4 address, eg. 152.78.224.83
- Link layer: Ethernet, 00:02:34:fe:34:66
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Term
What two things do you need in order to set up a new addressing resource (Network)? |
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Definition
- A unique name space to use
- A unique set of IP addresses to use
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Term
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Definition
| They manage the registration of domain names (SLDs) under one or more TLDs. |
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Term
| What is a Domain Name System? |
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Definition
- It provides a name-to-IP mapping service
- Delegation of authority to configure DNS usually passes with delegation of the namespace
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Term
| What is the Network Prefix Notation? |
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Definition
- IP addresses are 32 bit
- Writen in form 0-255.0-255.0-255.0-255
- Need a way to express size of a network allocated to ISP or to LAN
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Term
| What are Regional Internet Registries (RIRs)? |
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Definition
| An organization that manages the allocation and registration of IPs to ISPs within a particular region of the world |
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Term
| What are the range of TCP/UDP ports and which are the privileged ports? |
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Definition
- Range: 0 to 65535 (16 bits)
- Privileged: 0 to 1023
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Term
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Definition
| An application-specific or process-specific software construct serving as a communications endpoint in a computer's host operating system, which enables these applications or processes to enable them to share a single physical connection to networks(the internet). |
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Term
| What are the principles of Ethernet Addresses? |
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Definition
- 48 bit Ethernet/Mac Addresses
- Should not have duplicate Mac addresses in network
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Term
| Draw a diagram to show how a request-respond between a client and a server looks like throughout the TCP, IP and Link layers. |
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Definition
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Term
| How is addressing handled in the layers? |
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Definition
- Each layer (transport, network and link) sends data which is:
- A header, which includes the endpoint addresses being used
- The payload being sent
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Term
| What process does data ondergoes when passed through layers? |
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Definition
- Web browser does a GET request
- Passes data to transport layer
- Transport layer adds TCP header
- Passess TCP header and original data to the network layer as new payload
- Network layer adds IP header
- Passes IP header plus new data to link layer
- Link layer adds Ethernet header
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Term
| What does an Ethernet packet consist of? |
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Definition
Ethernet packet =
Ethernet header + IP header + TCP header + DATA |
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Term
| Show a diagram of layer encapsulation |
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Definition
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Term
| What does it mean by wrapping headers? |
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Definition
| Every time data is sent to a lower layer, the header of the current later is prefixed to the current data. |
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