Jak zadat atypickou sit. Masku

[Juraj Hilovsky]

----- Original Message -----
From: David Rohleder <davro na ics.muni.cz>
To: <linux na linux.cz>
Sent: Friday, January 26, 2001 12:14 PM
Subject: Re: Jak zadat atypickou sit. Masku


> hilovsky na unipo.sk (Juraj Hilovsky) writes:
>
> > ----- Original Message -----
> > From: Radek Skokan <skokan na lanprojekt.cz>
> > To: <linux na linux.cz>
> > Sent: Friday, January 26, 2001 10:26 AM
> > Subject: Re: Jak zadat atypickou sit. Masku
> >
> >
> > > Juraj Hilovsky wrote:
> > >
> > > > V kazdom pripade pre IP adresu triedy C je iba 5 pouzitelnych
masiek:
> > > >
> > > > 255.255.255.192
> > > > 255.255.255.224
> > > > 255.255.255.240
> > > > 255.255.255.248
> > > > 255.255.255.252
> > > >
> > > > ZIADNA INA MASKA NIE JE PLATNA PRE IP ADRESU TRIEDY C .
> > >
> > > Me to vychazi na 7, budu-li brat v uvahu jen masky, v jejichz sitich
je
> > sit =
> > > vic nez 1 stroj :-), jinak 8.
> > >
> > > /24    254 adresovatelnych zarizeni, broadcast, netcast
> >
> > Toto je cela siet C, maska 255.255.255.0, nepocital som ju do poctu
> > podsieti.
> >
> > > /25    126
> >
> > Je tu sice 126 hostov, ale zostal iba 1 bit pre sietovu cast IP adresy.
> > Ten moze mat hodnotu 0 alebo 1.
> > 0 je rezervovana pre adrseu siete triedy C.
> > 1 je rezervovana pre sietovy broadcast.
> > Zostava nam 0 bitov pre pouzitelne podsiete.
>
> Nesmysl, tak se to nepocita.
> Adresa site je sitova cast adresy doplnena samymi nulami. Tj. treba
> (adresa pocitace v siti) & netmask
> Sitovy broadcast je naopak sitova cast adresy doplnena samymi
> jednickami v host casti. tj. treba
> (adresa lib. pocitace v siti) | (~netmask)
>
> Takze broadcast pro sit A.B.C.0/25 je A.B.C.127

znova odporucam http://www.ralphb.net/IPSubnet

jh

>
> --
> -------------------------------------------------------------------------
> David Rohleder davro na ics.muni.cz
> Institute of Computer Science, Masaryk University
> Brno, Czech Republic
> -------------------------------------------------------------------------