Jak zadat atypickou sit. Masku

[Martin Mačok]

On Wed, Jan 24, 2001 at 10:23:02AM +0100, Petr Cech wrote:
> > Protoze neni tvaru posloupnost jednicek a pote posloupnost nul.
> 
> tim si nejsem uplne jist, ze to musi byt takhle za sebou. Nejake RFC?

Jak uz zminoval Milan Vymazal, je to napr. RFC 950.

> > Jak u site s lichou maskou chcete adresovat sit a broadcast? Co bude s tou
> > prvni nebo posledni lichou adresou?
> 
> broadcast je definovan jako "same jednicky v host casti", takze
> 1100 0001 je maska, sit si dame 0100 0000 a pak tedy broadcast je
> 0111 1110

Podlozim to temito citacemi z RFC 950:

*

      For example, the Internet address might be interpreted as:

         <network-number><subnet-number><host-number>

      where the <network-number> field is as defined by IP [3], the
      <host-number> field is at least 1-bit wide, and the width of the
      <subnet-number> field is constant for a given network.  No further
      structure is required for the <subnet-number> or <host-number>
      fields.  If the width of the <subnet-number> field is zero, then
      the network is not subnetted (i.e., the interpretation of [3] is
      used).

*

Z cehoz jsem usoudil, ze maska je jen "delitko", ktere rika "nalevo je
sit" a "napravo je host" a musi (nebo melo by (might)) byt kontinualni
- tedy nesmi se se obe casti nejak "prolinat".

Nicmene v examples se vyskutuje i:

*

   3.  A Class C Network Case (illustrating non-contiguous subnet bits)

      For this case, assume that the requesting host is on class C
      network 192.1.127.0, has address 192.1.127.19, that there is a
      gateway at 192.1.127.50, and that on network an 3-bit subnet field
      is in use (01011000), that is, the address mask is 255.255.255.88.

*

Coz situaci mirne komplikuje a budu rad, kdyz se odtedka budou k
situaci vyjadrovat jen ti, kteri OPRAVDU VEDI, JAK TO JE. (Ja uz se do
toho michat nebudu).

Preji hezky den

-- 
   Martin Mačok
  underground.cz
    openbsd.cz