IPv6 Abbreviation


if i  have this IPv6 Address

 

    1:0:3:0:5:6:7:8


why i can`t abbreviate this address to be:-

 

    1::3::5:6:7:8

 

::first

must be 0000

and second ::

must be 0000

so what is the problem if that specific address accepted :: and :: into same ipv6 address?????

------

another example

look




ipv6 address 1:0:3:0:5:0:7:8

could be 1::3::5::7:8

there`s not any Inevitable to be

first :: must represent 0

second represent 0

third 0

if anyone have the secrect of why  :: is to be used only once please tell me

Comments

  • JoeMJoeM ✭✭✭

    Major,

    This is an easy answer.  Must Know. It is in all books.  Be prepared for in all exams.

    For the example you gave, 1:0:3:0:5:0:7:8, only one of the 0's can be an ::.    Easy. Only one.

    If you had this 1:0000:0000:0000:3:0000:7:8,  where would use use your one wildcard ::  ?

     

    Anything to the left is filled with 0's automatically.

    :1: = :0001:

    :57: = :0057:

    :0:  = :0000:

     

    BUT again....only one :: is allowed.  It can fill out as many 0's as needed.

    :: can be   :0000:0000:0000:0000:    or   :0000:0000:   or   :0000:

    This depends on the IPv6 address being used.

     

    Just accept that this is the way it is.  Don't make studying difficult.   ;-)

     

    Let us know if this helps you Major.   Cheers!

  • Major,

     

    Just accept that this is the way it is.  Don't make studying difficult.   ;-)

     

    JoeM

    my name is mohamed from egypt

    ok thanks for your reply but there`re alots of questions that`s is inside your brain and makes you confused about topics and make you need to learn all details about something

     

    your answer is still don`t reply to my question

    1:0:3:0:5:0:7:8

    this address why don`t accept multiple ::

  • JoeMJoeM ✭✭✭

    Hello Mohamed from Egypt. We have exchanged posts frequently.  You usually are not so quick to reply back after people answer your questions. Happy to hear from you again so soon.  Hope your studies are doing well.

     

    Take a look at this puzzle:

     

    IPv6 address:     2001::3::5

    Can you identify the true ipv6 address?

    A. 2001:0000:3:0000:0000:0000:0000:5

    B. 2001:0000:0000:3:0000:0000:0000:5

    C: 2001:0000:0000:0000:3:0000:0000:5

    D. 2001:0000:0000:0000:0000:3:0000:5

    E:  all of the above

     

     

    EDIT: here is another one

    2001::1111::2222::

    What does this IPV6 address represent?

     

    2001:0000:1111:0000:2222:0000:0000:0000

    2001:0000:0000:1111:0000:2222:0000:0000

    2001:0000:0000:0000:1111:0000:2222:0000

    2001:0000:0000:1111:0000:0000:2222:0000

    2001:0000:1111:0000:0000:0000:2222:0000

    2001:0000:1111:0000:0000:2222:0000:0000

    2001:0000:1111:0000:2222:0000:0000:0000

     

    Do you see the problem with using multiple colons (::)?

     

  • hi JoeM  from mexico 

    you still don`t answer my question

    my question is that

    1:0:3:0:5:0:7:8

    this address why we cannot using multiple :: into it

    please explain into this example

  • JoeMJoeM ✭✭✭

    Not from Mexico.....but I do miss living in Mexico.  ;-)

     

    I think that I have answered your question.  Can you answer the puzzle that I gave you?  

    If you can answer the puzzle, then you will understand the reason for a rule like this.   If we identify a problem with multiple double-colons, why would we make exceptions for the rule.  That would make life very difficult, wouldn't it?

    Keep it simple. Solve the puzzle I gave you....and then you will understand the WHY.   ;-)

  • why would we make exceptions for the rule.  That would make life very difficult, wouldn't it?

    Keep it simple. Solve the puzzle I gave you....and then you will understand the WHY.   ;-)

    hi JoeM from Guadalajara, Mexico

    is the difficulity is the only reason that make ipv6 designer prevent from using multiple :: into same address?

    you still don`t answer my question with scientific answer that Heals nosy

    i need scientific answer not any answer

    i appretiate your efforts my friend JoeM from Guadalajara, Mexico [:D]

  • JoeMJoeM ✭✭✭

    is the difficulity is the only reason that make ipv6 designer prevent from using multiple :: into same address?

    Muhamed, I am very happy to help you with your doubts on this. I do not know any other reason than the one I have shown you.

    The issue should be very obvious with the above two examples I gave you.  You cannot break the rule just for your IPv6 address.  No exceptions for this rule.  

    Please let me know if you find another reason for this rule.  I do not know what you mean by a "scientific answer".  I really would like to know your final answer, if it is different from the reason that I have given you.

     

  • let me try. IPv6 address has 8 blocks separated by :

    The :: is used to abbriviate continuous blocks (one or many) of zeros.

    If there are two (or more) :: in ipv6 address, then you know total blocks are 8. But you donot know how many continuous blocks of zeros each :: abbriviates.

    If there is only one :: then, you know there are 8 blocks (say A) and you know how many blocks are given in textual (colon hexadecimal) ipv6 address (say B). Now you do A - B (ie 8 - B) which gives how many continuous blocks of zeros :: abbriviates. 

  • JoeMJoeM ✭✭✭

    Hi Martin, a mask is not needed for this example.   It can be whatever someone wants it to be.

     

     

    also see same post , topic, author at https://learningnetwork.cisco.com/thread/105366

     

    Wow!  He even copies and pastes the same responses on the other forum.   Everyone gives examples, but he is stuck on his special IPv6 address.     Wasting people's time by not listening and learning. 

    is the difficulity is the only reason that make ipv6 designer prevent from using multiple :: into same address?


    you still don`t answer my question with scientific answer that Heals nosy


    i need scientific answer not any answer

    • JoeM
    i don`t make any something bad , why you make post like this ?

    when i put post here and same post into another place that mean i don`t get the answer that`s iam looking for 

    i don`t want to waste time or something but what i want is to asking more people about something 

    if you see that my post is bad or you see iam silly please don`t reply for me again and don`t waste your time like what you said before  with me 

    ok thanks Martin from mexico
  • JoeMJoeM ✭✭✭

    i don`t get the answer that`s iam looking for 

    Muhamed,  This may be the problem. You are not listening to people, because you are looking for a certain answer. 

    I asked you more than once to look at the problems I outlined....but you refused.  That took my time, but you called it an "any answer". 

    I laughed when I saw you doing the same thing on the other forum.  People explain things clearly, and you repeat to everyone "you don't answer my question".

     

    As I have said to you many times, you ask great questions. This is very good, especially for someone who is still working on their CCNP.  You are thinking deeper into why/how, rather than just memorizing.   You will be very successful with this approach.      But maybe you can be more grateful and respectful to those who spend time helping you.

     

     

     

  • But maybe you can be more grateful and respectful to those who spend time helping you.

    iam so sorry

    but i think that you`re annoying from me , don`t understanding exactly what you need to say because your language is very hard and i don`t understanding exactly what you need to say

    i appretiate your efforts with me my friend

    but i need to say something to Martinl :-

    usually i will create posts here and into any other places i need , and i think it`s not wrong and i don`t make any mistake or don`t make any wrong , iam only asking question 

    if you see my question and see it again into another place, that means i don`t get good answer to my question and need more people to see my question if one person here into this blog reply to my question with good reply that i don`t receive from any other blogs or even from google or from  books , and i need people here to reply my question also

    Martinl 

    finally i want to say last thing to you

    if you think that what iam doing is bad please don`t reply to my question , or even don`t waste your time with me, please don`t forget what iam saying to you Martinl 

     

    iam sending special thanks to the polite person is called "JoeM"for his efforts with me, you`re so polite and iam sorry for my rough words , but i don`t understanding exactly your language , my native language is egyptian arabic

    "messi"the football player is here today in egypt , i hope to see him[:D]

  • JoeMJoeM ✭✭✭

    Muhamed,

    Let's get back to the IPv6 question about double colons :: -- only one allowed per address.

    Do you now understand what the rule is and why it is a necessary rule?    There is no magic to it at all.  It simply would not be possible for unicast, if devices started having overlapping IPv6 addresses.   In the other forum, it looks like someone copied a page of a book, and it shows what I laid out above.   

    Be kind to all, including Martin.  [;)]

  • JoeM

    the only reason that iam understanding is as you said is there`s not any exceptions into ipv6address because they don`t need to make ipv6 address more complex 

    i don`t have any problems with anyone include Martin, but i think he try to annoy me for reason i don`t know it

    my friend Martin

    i will happy if i see your reply but blease don`t say your words about copy/paste from another blog again beecause if make me feel that you`re hate me

    thanks

  • JoeMJoeM ✭✭✭

    No reason to continue with this negative view.  Everyone here is trying to help everyone.

    Some people just ask questions and do not say thankyo, nor do they try to help other people.  These are rude people just looking for free answers.

    But, many people do try to help others.  By helping others, they become better themselves.   Martin is one of those people.  He tries to help everyone, and he deserves our respect.  No argument is needed.

    Better for us to stay on the subject.   Just study.

     

    ....because they don`t need to make ipv6 address more complex....

    Probably better to say, because double-colons will make the IPv6 Address unreadable.  The solution for your IPv6 address is already provided with a single zero :0:     Possible for humans and machines to read this.

    Hope we helped you with this.  Keep studying.  ;-)

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