Ascend Archive
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: (ASCEND) how to calculate the 'ascend' netmask
On Mon, 15 Sep 1997, Thilo Wunderlich wrote:
> I can't find it in the max4000 manual:
> How do I calculate the 'ascend' netmasks ?
> Instead of 255.255.255.x /xx is used.
There is a chart on the Ascend website. I found one at the bottom of the
ascend p 25 quick setup.
Its pretty simple to figure out actually. Its based on # of bits. Like
this:
255.255.255.255, see the last chunk of the subnet mask, that 255 is base
10 and it equals 11111111 base 2. To subnet, you treat PART of that
11111111 as the network # and the other part as the ip range by changing
some of the 1's to zeros. For example to get a combo of 4 addresses, you
need to change the LAST 2 bits to 0, this is because the number 4 is the
maximum number capable of being represented in base 2 with 2 bits, 00, 01,
10, and 11. So the subnet looks like 11111100. since there are 4 PIECES to
the address, think of it as 32 bits, and we just took 2 bits away from the
network part of the address so now the "/" netmask would be 32-2 or 30. So
it would look like
address=192.168.1.0/30
this would give you the first 4 addresses out of 255 for that class C. Of
course you cannot use the first or last address cuz these are network #
and broadcast address, so with a /30 subnet, you only get 2 useable
addresses. With a /29 subnet you get 6 addresses which is 8 (11111000)-2.
Now this translates back to the standard netmaks by simply translating all
those 1's and 0's back into base 10. For example, 11111100 base 2 = 252
base 10, so the "real" netmask is 255.255.255.252.
Catching on?
> > Thilo > --
> thilo@vossnet.de Thilo Wunderlich Voss Net GmbH
> ++ Ascend Users Mailing List ++
> To unsubscribe: send unsubscribe to ascend-users-request@bungi.com
> To get FAQ'd: <http://www.nealis.net/ascend/faq>
>
~*-,._.,-*~'`^`'~*-,._.,-*~'`^`'~*-,._.,-*~'`^`'~*-,._.,-*~'`^`'~*-,._.,-*~
Jake Messinger 713-772-6690 jake@ams.com
Advanced Medical Systems, Inc. jake@uh.edu
8300 Bissonnet #400
Houston, Texas 77074 http://www.ams.com/~jake
~*-,._.,-*~'`^`'~*-,._.,-*~'`^`'~*-,._.,-*~'`^`'~*-,._.,-*~'`^`'~*-,._.,-*~
++ Ascend Users Mailing List ++
To unsubscribe: send unsubscribe to ascend-users-request@bungi.com
To get FAQ'd: <http://www.nealis.net/ascend/faq>
References: