LAN

[Christos Ricudis]

On Thu, 12 Jun 2003 11:50:54 +0300
Giannakis Eleftherios <legian at otenet.gr> wrote:

> > Sou diafeugei to oti to p.x. 10.0.0.0/8[1] diktuo mporei na to spasei se
> > osa epimerous diktua 8elei. Mporei na exei p.x. 2 subnets sto LAN tou,
> > ena 10.0.0.0/24 kai ena 10.0.0.128/24 .
>            ^^^^^^^^^^^^^^^^^^^^^^^^^^^
> 	   to /24 einai olokliro class C opote auto pou grafeis den einai sosto...
> 	   Mallon ennoouses 10.0.0.0/25 kai 10.0.0.128/25 (2 subnets apo 128)
> 	   h enoouses 10.0.0.0/24 kai 10.0.1.0/24 (2 class C's)

Na ti malakies ginontai otan skeftesai me classes. Sto CIDR den yparxei h ennoia
ths "subnetted class", otidhpote "a.b.c.d/z" kaleitai subnet. Sto CIDR ta arxika bits 
mias diey8ynshs (poy orizan thn "class" ths ston classfull world - ousiastika dhladh 
orizan ena DEFAULT network mask se routing entries kai tipote parapanw), den 
orizoun pleon tipote shmantiko. Opote sthn ousia kai h idia h leksh "subnet" stereitai
pleon tou arxikou ths nohmatos oson afora to prwto epipedo tou IP addressing.   

Etsi, DEN yparxoun "oloklhra class C". Oute class A, oute class B networks. To 10.0.0.0 
den orizei pleon apo mono tou oti "to network part einai ta aristerotera 8 bits kai ta 
ypoloipa orizoun to host part ths address".  Yparxoun /24aria subnets. To 10.0.0.0/24 
einai ena perfectly legal subnet ("ypodiktyo") tou ("diktyoy") 10.0.0.0/x gia ka8e x<24. 

To sygkekrimeno private allocation orizei ws private to 10.0.0.0/8. To 10.0.0.0/24 
einai ena proper subnet tou 10.0.0.0/8.

Eksallou ola ayta ephreazoun aplws kai mono to routing, kai tipote parapanw. Stamathste
na skefteste me classes. 

-- 
Christos Ricudis				ricudis at itc.auth.gr
Systems Administrator				+30-2310-998305
IT Support Center
Aristotles University of Thessaloniki, GREECE