Tugger the SLUGger!SLUG Mailing List Archives

Re: [SLUG] subnetting a subnet


Its Monday morning and you're not fully in gear yet Terry (8-)


-- 
Howard.
______________________________________________________
LANNet Computing Associates <http://www.lannet.com.au>

On Mon, 17 Jul 2000, Terry Collins wrote:

> David Ryan wrote:
> > 
> > G'day all,
> >         I have subnetted a class C address space into 4 blocks. I would like to
> > further subnet one of those blocks into say 2 or 4 subblocks.
> > 
> > I have read the mini-Howto but I am not sure how to do the
> > subsubnetting.
> 
> Well, it is Monday morning and what the heck. I'm not sure how it
> goes, but this is how I think it goes, which someone can correct if
> wrong.
> 
> 1 block    
>        192.168.1.0-255       netmask  255.255.255.0
                                        ^^^^^^^^^^^^^  correct
> 
> 2 blocks
>        192.168.1.0-127       netmask  255.255.255.128
                                        ^^^^^^^^^^^^^^^ correct
>        192.168.1.128-255     netmask  255.255.255.128
                                        ^^^^^^^^^^^^^^^ correct
> 
> 4 blocks 
>        192.168.1.0-63        netmask  255.255.255.64  <-- .192
>        192.168.1.64-127      netmask  255.255.255.64  <-- .192
>        192.168.1.128-191     netmask  255.255.255.64  <-- .192
>        192.168.1.192-255     netmask  255.255.255.64  <-- .192
> 
> 8 blocks
>        192.168.1.0-31        netmask  255.255.255.32  <-- .224
>        192.168.1.32-63       netmask  255.255.255.32  <-- .224
>        192.168.1.64-95       netmask  255.255.255.32   etc.
>        192.168.1.96-127      netmask  255.255.255.32 
>        192.168.1.128-159     netmask  255.255.255.32
>        192.168.1.160-191     netmask  255.255.255.32 
>        192.168.1.192-223     netmask  255.255.255.32
>        192.168.1.224-255     netmask  255.255.255.32
> 
> etc. Remember you loose the first and last (lowest and highest) out of
> each block as subnet/?? and broadcast address.

Correct.

The other subnet masks are:

16 blocks of 16 IPs .240
32 blocks of 8 IPs  .248
64 blocks of 4 IPs  .252  this is the lowest as it only gives you 2
useable addresses after the network and broadcast addresses have been
removed.

> 
> 
> --
>    Terry Collins {:-)}}} Ph(02) 4627 2186 Fax(02) 4628 7861  
>    email: terryc@xxxxxxxxxx  www: http://www.woa.com.au  
>        or terryc@xxxxxxxxxx 
>    WOA Computer Services <lan/wan, linux/unix, novell>
>    snail:  PO Box 1047, Campbelltown, NSW 2560.
> 
>  "People without trees are like fish without clean water"
> 
> 
> --
> SLUG - Sydney Linux User Group Mailing List - http://slug.org.au/
> More Info: http://slug.org.au/lists/listinfo/slug
>