192.168

Discussion in 'Linux Networking' started by bob, Oct 17, 2012.

  1. bob

    bob Guest

    Why is it that almost all LAN devices start with 192.168? Why such a strange and hard-to-memorize number?
     
    bob, Oct 17, 2012
    #1
    1. Advertisements

  2. Richard Kettlewell, Oct 17, 2012
    #2
    1. Advertisements

  3. bob

    ein Guest

    -----BEGIN PGP SIGNED MESSAGE-----
    Hash: SHA1

    It's easy when you use it 10 times a day.:)
    -----BEGIN PGP SIGNATURE-----
    Version: GnuPG v1.4.12 (GNU/Linux)
    Comment: Using GnuPG with Mozilla - http://www.enigmail.net/

    iEYEARECAAYFAlB+8yoACgkQbhT/MDrqNUHjIACff7OC1Br4Wb/2louyV+s7row2
    KAUAnj6gKXcG5Je7/339yEYzIlNZ6L8T
    =Z4hx
    -----END PGP SIGNATURE-----
     
    ein, Oct 17, 2012
    #3
  4. They are "round numbers" in the binary system. 192 dec is 300 oct.
     
    Maurizio Loreti, Oct 17, 2012
    #4
  5. bob

    Marc Haber Guest

    And really strange when your official IP range is from 194.162/16.

    Greetings
    Marc, btdt
     
    Marc Haber, Oct 17, 2012
    #5
  6. bob

    ein Guest

    -----BEGIN PGP SIGNED MESSAGE-----
    Hash: SHA1

    198.162 would be better. ;)

    -----BEGIN PGP SIGNATURE-----
    Version: GnuPG v1.4.12 (GNU/Linux)
    Comment: Using GnuPG with Mozilla - http://www.enigmail.net/

    iEYEARECAAYFAlB/FvEACgkQbhT/MDrqNUEqpQCfQKe24HfUy8+6jqo3v/PFh8O0
    WLUAoLiOe3Ck3GwyG0LGoMmfhrhXE9No
    =fAZl
    -----END PGP SIGNATURE-----
     
    ein, Oct 17, 2012
    #6
  7. bob

    unruh Guest

    And why would you want to memorize it?
    That is a private address reange, non-routable on the internet. Used by
    networks which use dhcp to supply temporary addresses to clients.
     
    unruh, Oct 18, 2012
    #7
  8. Johann Klammer, Oct 18, 2012
    #8
  9. bob

    Vanni Guest

    this is a privat IP
     
    Vanni, Oct 18, 2012
    #9
  10. There’s no particular connection between the private address ranges and
    dynamic addressing. It’s perfectly possible to use fixed private
    addresses or dynamic globally routable addresses.
     
    Richard Kettlewell, Oct 18, 2012
    #10
  11. bob

    Marc Haber Guest

    198/8 was not allocated back when my connected hosts were in
    194.162/16. Since then, I made it a habit to check IP addresses for
    mixed digits first thing in debugging.

    Greetings
    Ma "192.162, 194.168" rc
     
    Marc Haber, Oct 18, 2012
    #11
  12. bob

    ein Guest

    -----BEGIN PGP SIGNED MESSAGE-----
    Hash: SHA1


    IMHO there's no such thing like non-routable IP address range, but
    more safe definition would be that private IP address ranges should be
    excluded (filtred) in the Internet. Common ISPs mistake is that
    private ranges are in routing tables or even announced by their BGP
    routers.


    -----BEGIN PGP SIGNATURE-----
    Version: GnuPG v1.4.12 (GNU/Linux)
    Comment: Using GnuPG with Mozilla - http://www.enigmail.net/

    iEYEARECAAYFAlCA6mEACgkQbhT/MDrqNUHpQQCfQNiv76oD6GH0ZBkgAgaQiMjt
    hOUAoKgmAaIyXlsILuu9TyUa5YZxQtKT
    =eY7k
    -----END PGP SIGNATURE-----
     
    ein, Oct 19, 2012
    #12
  13. bob

    ein Guest

    -----BEGIN PGP SIGNED MESSAGE-----
    Hash: SHA1

    It hurts when I'm looking at these addresses. :)

    -----BEGIN PGP SIGNATURE-----
    Version: GnuPG v1.4.12 (GNU/Linux)
    Comment: Using GnuPG with Mozilla - http://www.enigmail.net/

    iEYEARECAAYFAlCA6wsACgkQbhT/MDrqNUEJ4QCfW8bXTzX7+fIjp3T4fsSx5AvJ
    cuMAoIrKLCufU+2ez53koQBam70qCpmm
    =v99K
    -----END PGP SIGNATURE-----
     
    ein, Oct 19, 2012
    #13
  14. bob

    Noob Guest

    The address ranges defined in RFC1918 are non-routable by definition.
    https://tools.ietf.org/html/rfc1918

    Because private addresses have no global meaning, routing information
    about private networks shall not be propagated on inter-enterprise
    links, and packets with private source or destination addresses
    should not be forwarded across such links. Routers in networks not
    using private address space, especially those of Internet service
    providers, are expected to be configured to reject (filter out)
    routing information about private networks. If such a router receives
    such information the rejection shall not be treated as a routing
    protocol error.
     
    Noob, Oct 19, 2012
    #14
  15. bob

    orcus Guest

    Usage of term "non-routable" is misleading. If you want you can
    set up routes for private addresses. Every subnet using "non-routable"
    addresses has routing set up for them(default gateway or on-link routes
    at least).
     
    orcus, Oct 19, 2012
    #15
  16. bob

    Jorgen Grahn Guest

    "Non-routable as far as the Internet is concerned", then?

    /Jorgen
     
    Jorgen Grahn, Oct 20, 2012
    #16
  17. bob

    orcus Guest

    Nope - a lot of ISPs use privete adresses to connect their routers.
    They only block trafic with wrong private or source destinations on
    interfaces connected directly to clients. Sometimes we can see
    "non-routable" adsresses in output of traceroute - somewere in
    "Internet".
     
    orcus, Oct 20, 2012
    #17
  18. bob

    Jorgen Grahn Guest

    Those ISPs are violating RFC1918, and do not count. If an address
    shows up in traceroute output, I should be able to access it.

    /Jorgen
     
    Jorgen Grahn, Oct 20, 2012
    #18
  19. Hello,

    Noob a écrit :
    There are : link-local scope addresses such as 169.254.0.0/16 or
    fe80::/10 are non routable, i.e. they should not be forwarded by any
    router on either private or public networks.
    But when Unruh wrote "non-routable on the internet", I guess it meant
    the public internet.
    No. Private addresses are perfectly routable on a private network. They
    should just not be routed on the public internet across separate networks.
     
    Pascal Hambourg, Oct 20, 2012
    #19
  20. bob

    orcus Guest

    Which fragment fragment of RFC they violate? They use private addresses
    inside their network and filter out routing information about this
    subnets. I see no violation. Moreover using 4 IP addresses from ranges
    assigned to ISP for point to point links is a waste of IPv4 addresses.

    If we exclude ISPs from our discussion we still can use 10
    subnets with private addresses in our company and set up routing for
    them(even dynamic). The point is that calling RFC1918 addresses
    "non-routeable" is semantic abuse*.

    *) Is "semantic abuse" correct phrase in English?
     
    orcus, Oct 20, 2012
    #20
    1. Advertisements

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.