Confusion between Ethernet, MAC, and data link layer

roghanroghan ■■□□□□□□□□ Posts: 33Member ■■□□□□□□□□
I'm studying for CCNA by one week, and in particular I'm in Chapter 1 (Introduction to networking basics). I understood that each layer has its protocols: Application-HTTP/FTP/..., Presentation-SSL/...,... However, I have a bit confusion about Ethernet and MAC icon_confused.gif:. MAC is a sub-layer of Data link layer (together LLC), ok, but is it even a protocol, right? Instead what is Ethernet?? A protocol? Another sub-layer?

thanks :D

Comments

  • capitanuionutcapitanuionut ■■□□□□□□□□ Posts: 55Member ■■□□□□□□□□
    roghan wrote: »
    I'm studying for CCNA by one week, and in particular I'm in Chapter 1 (Introduction to networking basics). I understood that each layer has its protocols: Application-HTTP/FTP/..., Presentation-SSL/...,... However, I have a bit confusion about Ethernet and MAC icon_confused.gif:. MAC is a sub-layer of Data link layer (together LLC), ok, but is it even a protocol, right? Instead what is Ethernet?? A protocol? Another sub-layer?

    thanks :D

    Ethernet is a standard. It defines :
    - the pshysical cables for connecting equipment at physical layer.
    - how frames are encapsulated at Layer 2.
    - how different equipments have access to the network (CSMA/CD). -

    The OSI model is a reference/theoretical model on wich all these standards and protocols have been created, it's not something like a protocol wich has it's rules and all that.
    I'm not sure i was very clear but i hope i helped.
  • thedramathedrama Posts: 291Member
    roghan wrote: »
    I'm studying for CCNA by one week, and in particular I'm in Chapter 1 (Introduction to networking basics). I understood that each layer has its protocols: Application-HTTP/FTP/..., Presentation-SSL/...,... However, I have a bit confusion about Ethernet and MAC icon_confused.gif:. MAC is a sub-layer of Data link layer (together LLC), ok, but is it even a protocol, right? Instead what is Ethernet?? A protocol? Another sub-layer?

    thanks :D

    Yeah, Ethernet is a standard which uses both physical layer and data-link layer to operate. It defines a communication between hosts which reside on the same link and sharing that link. Nowadays, Ethernet is known as the only LAN standard because token ring and others are not found attractive. icon_cheers.gif

    MAC is the media access control address as the name suggests which allows your computer to communicate on the LAN. Moreover, it provides access to
    media such as cables or wireless media. This address makes your machine
    unique and identifiable on the LAN. Without MAC addresses your packet
    will never be prepared to be transmitted hence packets must track
    all OSI layers from top to down and they have to be released to the media
    "physically." while IP addresses are not physical but logical.
    Monster PC specs(Packard Bell VR46) : Intel Celeron Dual-Core 1.2 GHz CPU , 4096 MB DDR3 RAM, Intel Media Graphics (R) 4 Family with IntelGMA 4500 M HD graphics. :lol:

    5 year-old laptop PC specs(Toshiba Satellite A210) : AMD Athlon 64 x2 1.9 GHz CPU, ATI Radeon X1200 128 MB Video Memory graphics card, 3072 MB 667 Mhz DDR2 RAM. (1 stick 2 gigabytes and 1 stick 1 gigabytes)


  • roghanroghan ■■□□□□□□□□ Posts: 33Member ■■□□□□□□□□
    Thanks capitanuionut and thedrama icon_thumright.gif. I think I understand what Ethernet is and the differences between Ethernet, MAC, data link and phisical layer. Hence, Ethernet is a standard for layer 2 and 1 that defines the communication process, while LLC and MAC are sub-layer for layer 2. Ok. The last question... What does IEEE 802.3 mean??? Is it referred to Ethernet standard?
  • okplayaokplaya Posts: 199Member
    roghan wrote: »
    The last question... What does IEEE 802.3 mean??? Is it referred to Ethernet standard?

    Yes, 802.3 is the IEEE standard specification for ethernet. You have 802.3u, 802.3z, etc. Most standards have some sort of reference, but with 802.3 in particular, we commonly use 'FastEthenernet, GigabitEthernet', and so forth.

    Notice for WLAN standards we use the actual IEEE specification (802.11a/b/g/n) instead of a regular name such as "FastWireless, SuperFastWireless, etc"

    HTH
  • capitanuionutcapitanuionut ■■□□□□□□□□ Posts: 55Member ■■□□□□□□□□
    okplaya wrote: »
    "FastWireless, SuperFastWireless, etc"

    HTH

    You made my smile... but if this standards were called like this i think it would be easier to remember the differences between them and all that...at least with Ethernet it's clear from name that FastEthernet is better:Dafter that you only need to remember why it is.
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