Could he use the range 38.29.63.0 with a subnet of 255.255.252.0 to block
the violating IP's?
-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED]]On Behalf Of Peter Salvage
Sent: Monday, November 01, 1999 5:10 PM
To: [EMAIL PROTECTED]
Subject: Re: [IMail Forum] netmask for killing spam from ip range
The netmask is used to split a network of IP addresses into a collection
of smaller networks. A subnet mask is the mechanism that defines how the
host portion of the IP address is divided into subnetwork addresses and
local host address portions. IP addresses are represented by 4 sets of
octets: 123.456.789.123 thus in a /24 or as is commonly (and
erroneously) known, a Class C range of IP's, the netmask is
255.255.255.0 which means that 24 of the available 32 bits are set,
starting from most important to least important (left to right).
In binary everything is either 1 or 0 right? So, look at the decimal
notation of a /24 again: 255.255.255.0. It's 4 octets, which means
there's 4 rows of 1's or 0's. We already know the first three are all
1's (maximum value of 255) and therefore by extension we know the LAST
octet must be all 0's (minimum value of 0). It's easy to work out too:
128 64 32 16 8 4 2 1
1 1 1 1 1 1 1 1
The above is a decimal representation of an octet. The top row is the
value, the bottom row is the binary. So, if we want 255, we make them
all 1's. Add all the values in the top row up. Yep, we get 255. Get it?
Now, the binary representation of that "Class C" we were talking about:
(255) (255) (255) (0)
11111111 11111111 11111111 00000000
Add up the 1's this time. Yep, there's 24...that's why we call it a /24
</class>
</soapbox>
/wiZZ
----- Original Message -----
From: Sales <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: 02 November 1999 01:31
Subject: Re: [IMail Forum] netmask for killing spam from ip range
> ooops that is what i meant. typo.
> thanks
>
> At 02:07 PM 11/1/99 -0500, you wrote:
> >If you're going to do something so radical.. at least contain the
damage...
> >
> >Try 38.29.63.0, 255.255.255.0
> >and 38.29.64.0, 255.255.255.0
> >
> >----- Original Message -----
> >From: Sales <[EMAIL PROTECTED]>
> >To: <[EMAIL PROTECTED]>
> >Sent: Monday, November 01, 1999 1:56 PM
> >Subject: [IMail Forum] netmask for killing spam from ip range
> >
> >
> >> getting a lot of spam from these ips
> >> 38.29.64.243
> >> 38.29.63 .84
> >> 38.29.64.91
> >>
> >> so i am just going to kill the whole range.
> >> 38.29.0.0
> >> is the proper netmask 255.255.0.0 ?
> >> still haven't gotten the hang of the netmask yet.
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