none
Does "reserved" mean "non-routed on internet"? RRS feed

  • Question

  • Have I understood correctly that
    (1)
    169.254.x.x ranges - are reserved for APIPA, i.e. for private use on internal network
    (2)
    224-239.x.x.x - reserved for multicast addressing
    (3)
    240-254.x.x.x - reserved for experimental use.
    and
    (4)
    IANA-reserved private network ranges are:
    10.0.0.0 – 10.255.255.254,
    172.16.0.0 – 172.31.255.254,
    192.168.0.0 – 192.168.255.254
    ?

    What is the need of separate reservation for experimental use (3)?
    i.e. why the experimentators could not have sufficed with "IANA-reserved private network ranges" (4)?
    or
    Why  could not "experimental" (3) be called as (4) "reserved private"?


    Does it mean that addresses (3) are routed on internet?

    What are possible problems in my using (3) "experimental" addresses in local network?
    i.e what is the differences between (3) and (4) 

    Does "multicast", "APIPA", "experimental", "reserved"  imply (contain in its meaning) the meaning "for internal network", i.e non-routed in internet?

    Saturday, July 24, 2010 3:04 AM

Answers

  • (3)
    240-254.x.x.x - reserved for experimental use.
    Does it mean that addresses (3) are routed on internet?

    No, they are not, and cannot be.

    What are possible problems in my using (3) "experimental" addresses in local network?
    i.e what is the differences between (3) and (4) 

    Multicasting is used for a variety of applications that send the same packet to multiple hosts, such as in video or audio simultcasting, and computer drive imaging software to send the same TCP/IP packets to multiple machines, essentially the multicast packets have multiple recipient hosts (multiple destination addresses), versus non-multicasting which has only one recipient host (the destination address).

    For example, when I use Ghost to setup 16 student machines for a classroom, I setup the "Ghost Cast" service in the Ghost Service Console and choose a Ghostcast session name, tell it to listen for 16 machines before starting to "cast" the data, then go to each machine and run a DOS DC with the Ghost client side, tell it to look for the Ghost Session name, then click "go." Once I hit the 16th machine, the cast starts. This prevents 16 separate TCP/IP sessions, so literally 16 machines receive the same packet and use it, otherwise if I setup 16 separate sessions without using the Ghostcase feature, it will bog the network down to a crawl becuase there are 16 individual sessions running on the network and each machine will ignore the other 15 that was not meant for it. With this feature all will accept and process the same packet, so essentially it "looks" like one session on the wire but with 16 recipients.

    This address range is purely private and is not routed on the internet. It is up to the application to know how to use it. The multicast server sends out the packets and you would have to install the app's client side to receive the packets.

    > Does it mean that addresses (3) are routed on internet?

    No, neither of these ranges are publicly routable. Multicasting can be routed internally, but I have not used the experimental range to know, but I assume it is as well.

    > What are possible problems in my using (3) "experimental" addresses in local network?
    i.e what is the differences between (3) and (4)
     

    They're still experimenting. I'll let you know when they come up with their report. :-)

    Realistically, your #3 is for IP experimentation, but I don't have any examples. If you ask me, they probably don't use it anymore now that IPv6 is out. Your #4 is multicasting, which is being used, as defined in my previous paragraphs.


    Ace Fekay, MVP, MCT, MCITP EA, MCTS Windows 2008 & Exchange 2007, MCSE & MCSA 2003/2000, MCSA Messaging 2003, Microsoft Certified Trainer, Microsoft MVP - Directory Services. This posting is provided AS-IS with no warranties or guarantees and confers no rights.
    • Edited by Ace Fekay [MCT] Saturday, July 24, 2010 4:45 PM Provided a response to "> Does it mean that addresses (3) are routed on internet?"
    • Marked as answer by vgv8 Sunday, July 25, 2010 1:30 AM
    Saturday, July 24, 2010 4:44 PM