Date: Wed, 27 Aug 2003 17:47:08 -0400 From: "Clark Gaylord" <cgaylord@vt.edu> To: "'Christoffer Pio'" <cp@cvt.dk> Cc: freebsd-net@freebsd.org Subject: RE: subnetting C class into /26 /25 /26, why can this be done? Message-ID: <715379D39F6E534594B4B3182B6365900302EA2C@fangorn.cc.vt.edu> In-Reply-To: <3F4CBA6A.5AA7DEB0@cvt.dk>
next in thread | previous in thread | raw e-mail | index | archive | help
When in doubt, do it in binary:
0 =3D 00000000
64 =3D 01000000
128 =3D 10000000
192 =3D 11000000
As a /26 (taking as given the 24 x's not shown for the other three =
octets):
xxyyyyyy - y's are the host
xx doesn't have the same value from 64-191
As a /25:
xyyyyyy - y's are the host
x doesn't have the same value from 64-191
A /26 means there are 26 bits of network and 6 bits of host; a /25 means =
25
bits of network and 7 for host.
As /26's xx =3D {00, 01, 10, 11} for the four distinct values, with the =
other
six bits signifying the host address. As /25s x =3D {0, 1} are the two
distinct values. Now, you could use 0/25 (as 0-127 all have same first =
bit)
and 128/26 and 192/26 as each of these network address bits (10 and 11) =
stay
the same through the respective block of addresses.
Hopefully this helps.
Clark
> -----Original Message-----
> From: owner-freebsd-net@freebsd.org=20
> [mailto:owner-freebsd-net@freebsd.org] On Behalf Of Christoffer Pio
> Sent: Wednesday, August 27, 2003 10:04 AM
> To: freebsd-net@freebsd.org
> Subject: subnetting C class into /26 /25 /26, why can this be done?
>=20
>=20
> Is it not possible to subnet a C class into 3 nets, like
>=20
> 0-63
> 64-191 <-- Offending network (?)
> 192-255
>=20
> If so, why is this?
>=20
> Christoffer
> _______________________________________________
> freebsd-net@freebsd.org mailing list=20
> http://lists.freebsd.org/mailman/listinfo/f>; reebsd-net
> To=20
> unsubscribe, send any mail to=20
> "freebsd-net-unsubscribe@freebsd.org"
>=20
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?715379D39F6E534594B4B3182B6365900302EA2C>