1 / 21

Network Addressing

Level 2 Diploma Unit 10 Setting up an IT Network. Network Addressing. OSI Layers 1 to 4. OSI Physical layer 1 Network media – the cables/wireless and adapters OSI Data link layer 2 Method of transferring data between network adapters Organises data streams into frames Uses MAC addresses

dreama
Download Presentation

Network Addressing

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Level 2 Diploma Unit 10 Setting up an IT Network Network Addressing

  2. OSI Layers 1 to 4 • OSI Physical layer 1 • Network media – the cables/wireless and adapters • OSI Data link layer 2 • Method of transferring data between network adapters • Organises data streams into frames • Uses MAC addresses • OSI Network layer 3 • Routes packets between networks • Uses IP addresses

  3. OSI (Open Systems Interconnect) model • 7 layers • Each layer provides a service for the layer above and uses the services of the layer below • Each layer (except the physical) attaches a header • Headers provide control information

  4. Frames • Address used is the 48 bit unique MAC (Media Access Control) address hard coded into the adapter

  5. Network Layer 3 • Data messages are split into smaller packets • Better chance of successful delivery • Easier to resend if lost or damaged • Routers • Choose the path that packets take around the network • Packets are given a time to live (TTL) to prevent them travelling for ever • Internet Protocol (IP) and IP addressing • Provides network identification and addressing • An IP address is a 32 bit binary value expressed as dotted decimal 00001010.00000001.1010000.00001100 is easier as 10.1.80.12

  6. Restricted addresses

  7. I. P Addresses 11000000101010000000000100000101 What is a ’bit’? 192.168.1.5 www.

  8. Network Address Translation • Private networks connect to the Internet via a router • Host’s private address is translated to a valid public address by the router using NAT • Easier IP configuration • Hosts protected from direct internet access • Can map 1:1 or use port addresses to map n:1

  9. ARP and ICMP • ARP (Address resolution protocol) • Network layer • Converts IP addresses to MAC addresses • Converts MAC addresses to IP addresses • ICMP (Internet control message protocol) • Used for diagnostic and troubleshooting tools • PING • TRACERT

  10. TCP and UDP Layer 4 • TCP Transmission Control Protocol • Reliable • Connection oriented packet transfer • TCP/IP applications use a unique identification number called a port • An IP address and a port make a socket • Socket to socket connections make a path • http:215.58.254.252:80 where 80 is the port number

  11. Common port numbers

  12. HTTP and HTML • Hypertext transfer protocol • Web browsers request resources from web servers by • connecting to port 80 • Using a Uniform Resource Identifier (URI) • Common web servers are • Apache (open source) • Microsoft Internet Information Server (IIS) • HTTP is used to serve HTML (Hypertext MarkUp language) pages which describe how the text should be displayed

  13. SSL/TLS • HTTP is not encrypted and does not authenticate • SSL (Secure sockets layer) and TLS (Transport Layer Security) • Provide cryptographic security • Used with HTTPS • Uses port 443 • Puts https:// in the URI • Adds a padlock icon in the browser

  14. E-mail • Plain text • File attachments encoded in MIME (multipurpose internet mail extensions) • Send mail out using SMTP • Simple mail transfer protocol • Receive mail using • POP3 or IMAP4 • Can be secured using PGP (Pretty Good Privacy or Secure MIME

  15. FTP • File transfer protocol • More efficient then e-mail • Plain text transfer • Most browsers include an FTP client • ftp://ftp.microsoft.com/

  16. Instant Messaging • Exchange of text messages with contacts

  17. Domain names • Every host on the internet has a unique, 32 bit IP address • For convenience each host also has a Fully Qualified Domain Name (FQDN) • Domain Name Servers cross reference between domain names and IP addresses • An FQDN is hierarchical • www.google.comwww as a local domain indicates the resource is a web server • A Subdomain has to be registered and identifies a company, organisation or individual Top level domain local domain Subdomain

  18. Top level domain names

  19. Uniform Resource Identifier • A URI (sometimes known as a URL): • Has all the information to identify a resource • http://news.bbc.co.uk/1/hi/sci/tech/8013709.stm • http:// is the protocol being used • News.bbc.co.uk is the FQDN • /1/hi/sci/tech/8013709.stm is the file path on the server

  20. email address • An email address consists of: • The user name • A separator symbol (@) • A domain name • prossert@hct.ac.uk

  21. Task (criteria P5) • You have been asked by a friend to explain how network communications work in a company. Describe how hardware, software and addressing combine to use a web browser to send an e-mail to another system. • Include a diagram making sure you show how the components are connected together • Make sure you explain: • NIC, cable, switches, routers, modems, servers • NOS, E-mail client, web browser • IP and MAC addresses

More Related