Re: Help with Subnet Mask

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Article #35

#35

From: James Carlson
Date: Tue, 28 Mar 2000 00:00

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"Watchman" <lewy@yebo.co.za> writes:
> If you were given an IP address of 176.58.24.1 for your machine, but no
> subnet mask, what subnet mask could you use by default?
> 
> A - 255.0.0.0
> B - 255.255.0.0
> C - 255.255.255.0        or
> D - 255.255.255.255

Classful addressing is as dead as the person who put this question on
your homework assignment.  ;-}

The correct answer is "E" -- none of the above.  You can't use an IP
address on a multi-access-type interface without an assigned subnet
mask.  You can't.  Period.  There are no "default" values that are
useful.

The answer wanted, however, is likely to be B (255.255.0.0), since in
the pre-CIDR days, that particular address would have been a class B
address.

-- 
James Carlson, System Architect                     <carlson@ibnets.com>
IronBridge Networks / 55 Hayden Avenue   71.246W   Vox:  +1 781 372 8132
Lexington MA  02421-7996 / USA           42.423N   Fax:  +1 781 372 8090
"PPP Design and Debugging" --- http://people.ne.mediaone.net/carlson/ppp

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From: James Carlson <carlson@ironbridgenetworks.com>
Subject: Re: Help with Subnet Mask
Date: 2000/03/28
Message-ID: <86g0tawzh5.fsf@ironbridgenetworks.com>
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