[3990] in linux-net channel archive
Re: Subnetting, Arghh
daemon@ATHENA.MIT.EDU (Henry W Miller)
Sat Aug 10 03:21:41 1996
Date: Fri, 9 Aug 1996 07:11:50 -0500 (CDT)
From: Henry W Miller <mill0440@gold.tc.umn.edu>
To: Mogens Melander <mogens@frontier.dk>
cc: Linux Net <linux-net@vger.rutgers.edu>
In-Reply-To: <320A7BDB.12DE@frontier.dk>
This depends on your setup. It looks like you want 5 subnets, in which=
=20
case you would need a mask of 255.255.255.31, providing up to 30 hosts =
on=20
each network. This will not fit your scheme, but it is close enough th=
at=20
you may wish to make it work. you will have up to 8 different subnets=20
avaibal in this case. (32*8=3D256) if you need more hosts on a networ=
k,=20
some routers may be able to handle a variable subnetmask, so you could=20
make the first 4 networks 255.255.255.31, and the final one=20
255.255.255.127, allowing one big network of 126, and 4 smaller ones of=
=20
30. (the fisrt network would be x.x.x.0-x.x.x.31, second 32-63,=20
64-95,96-127, and the final one x.x.x.128-x.x.x.255) I'm not sure if=20
linux can handle this scheme though, and if it can you may not be able =
to=20
use rip on the network. ospf ought to work, but static routes are the=20
easiest way to route. =20
I woudl recomend the 255.255.255.31 mask, and just stick to 30 hosts pe=
r=20
network. If you need to you can use this setup:
internet
|
|
|---hosts that you want on this network
|
|
|--linux (or comercial router)=3D=3D=3D=3D=3D=3D several networks
|
|
|---linux (or comercial router)=3D=3D=3D=3D=3D=3Dseveral more networks
this setup will get around both the limit of the number of hosts on a=20
network, the number of cards in a PC, and the bandwadth avaibal in a PC=
=20
bus. =20
On Fri, 9 Aug 1996, Mogens Melander wrote:
> Hi,
>=20
> After reading lots of descriptions, i'm not less confused.
>=20
> I'm having this idea, that i just can't figure out. There must
> be some wizards out there who know all about this, i hope.
>=20
> I have a class C network, and i want to keep 30 adresses to
> my own net and route the rest to different size subnets.
>=20
> My vision looks something like this
>=20
> +--------------------+---------------+-----------+ +--->
> internet
> | | | | |
> +------+------+ +-----+----+ +-----+-----+ +-+---+-+
> |linux | |nameserver| |www server | |router |
> |pppd / diald | |mailserver| |ftp server | +-------+
> +-+--------+--+ +----------+ +-----------+
> | |
> | |
> ttyS0 +---- Net A ( 6 hosts)
> ttyS1 |
> ttySn +---- Net B (14 hosts)
> |
> +---- Net C (14 hosts)
> |
> +---- Net C (14 hosts)
>=20
> Given this layout, what would my addresses/netmasks look like ?
>=20
> Any ideas anybody ?
>=20
> --=20
> Later
> +-----------------------------------------------------------+
> + Mogens Bue Melander mailto:mogens@frontier.dk +
> + Mosevangen 52 http://www.frontier.dk +
> + 3460 Birker=F8d Phone +45 42 81 40 52 +
> + Denmark Mobil +45 40 74 42 43 +
> +-----------------------------------------------------------+
>=20
