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Re: net mask

Hi,

About the calulator:
The subnetmask it calcultates is sane but assumes that there is no sub (or
super) networking going on. This is the source of loads of confusion about
classes vs netmasks (i've had to convince several that they *are* related
but *not* the same).

Happy reading.
(thanks for tip on not cc'ing..... if i offended anyone, sorry!)

Yours,
Nico de Haer

----- Original Message -----
From: Jimmy Richards <longshot@c243491-a.aurora1.co.home.com>
To: <debian-user@lists.debian.org>
Sent: Tuesday, June 26, 2001 10:32 AM
Subject: Re: net mask


On Mon, Jun 25, 2001 at 10:22:05PM +0200, nico de haer wrote:
> Jimmy,
>
> I'd like to point out that it is NOT possible to calculate the netmask.
(at
> best you can calculate the network class). The problem is that you can't
> tell if there is some sub (or super) networking going on. so your only
> option is to *ask* the provider. (see ip-subnetworking howto)
>
> regards,
> Nico de Haer

Hello Nico,

Thank you for pointing out the correct way to get the proper netmask
for ip's that are given to you by your network provider. I have a couple
of books on networking I recently purchased, and will read them and the
ip-subnetworking howto that you suggest. I couldn't help but wonder if
the calculator gave the correct answer. I put my own ip in and it didn't
answer with the subnet mask that my isp gave me. I then downloaded a
newer version of the calculator, that was several versions newer, and it
still didn't give the same subnet mask my isp gave me. So I figured I
had better start doing some reading. I assumed the calculator would give
a proper answer, but I should have known it wouldn't be that simple when
it comes to networking.
There is one thing that I hope you don't mind me pointing out to you
Nico. It is considered unpolite netiquette to 'cc' someone in on your
reply to the mailing list, unless they have requested it. I have seen
some people respond as if they consider it to be pretty rude. It's no
big deal to me, but in the future you might want to reply to the mailing
list only, fyi. Thanks again for pointing out the error of my ways.


Cheers,

Jimmy Richards



> ----- Original Message -----
> From: Jimmy Richards <longshot@c243491-a.aurora1.co.home.com>
> To: <debian-user@lists.debian.org>
> Sent: Monday, June 25, 2001 10:04 PM
> Subject: Re: net mask
>
>
> On Mon, Jun 25, 2001 at 09:14:49PM +0200, Daniel de los Reyes wrote:
> > My provider has assigned me the following ip range
> > 213.201.43.208-15
> > what net mask should I use?
>
> Hi Daniel,
>
> I used a network calculator to get the following information.
> According to it you should use a netmask of 255.255.255.0.
>
>
>
> longshot@c243491-a:~$ ipcalc.pl 213.201.43.208
>
> Address:   213.201.43.208        11010101.11001001.00101011 .11010000
> Netmask:   255.255.255.0 == 24   11111111.11111111.11111111 .00000000
> Wildcard:  0.0.0.255             00000000.00000000.00000000 .11111111
> =>
> Network:   213.201.43.0/24       11010101.11001001.00101011 .00000000
> (Class C)
> Broadcast: 213.201.43.255        11010101.11001001.00101011 .11111111
> HostMin:   213.201.43.1          11010101.11001001.00101011 .00000001
> HostMax:   213.201.43.254        11010101.11001001.00101011 .11111110
> Hosts/Net: 254
>
>
> longshot@c243491-a:~$ ipcalc.pl 213.201.43.215
>
> Address:   213.201.43.215        11010101.11001001.00101011 .11010111
> Netmask:   255.255.255.0 == 24   11111111.11111111.11111111 .00000000
> Wildcard:  0.0.0.255             00000000.00000000.00000000 .11111111
> =>
> Network:   213.201.43.0/24       11010101.11001001.00101011 .00000000
> (Class C)
> Broadcast: 213.201.43.255        11010101.11001001.00101011 .11111111
> HostMin:   213.201.43.1          11010101.11001001.00101011 .00000001
> HostMax:   213.201.43.254        11010101.11001001.00101011 .11111110
>
>
> HTH,
>
> Jimmy Richards
>
>
> > --
> > ______________________________
> > Daniel de los Reyes
> > S2-Desarrollo, Grupo S2
> > Valencia Spain
> > e-mail: dadecal@s2-selling.com
> > Powered by Debian GNU-Linux 2.2r3
> > ______________________________
> >
> >
> > --
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>
>
>
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