Re: Subnetting Problem by Marko
Marko
Tue Jul 15 04:37:29 CDT 2003
Jeffrey Woods has provided the best answer so far.
Your ISP may not be a total idiot for "assigning" this IP
space in the first place. It would only work on your
10.24or30.y.z network and possibly to reach the ISP's
servers / routers and that is likely it. However, if the
ISP provides mail and proxy servers (possibly other
services?) then this IP assignment is OK.
10.24.x.y to 10.30.a.b would require a mask of 255.248.0.0
to cover all those IP ranges mentioned.
The 10.24.x.y ranges could be covered by "route add
10.24.32.0 mask 255.255.253.0 (gateway IP here)"
...Assuming 10.30.39.9/24 is a typo and should be
10.30.39.0/24 (cause the first is definitely wrong and
does not exist)...
Then route add 10.30.35.0 mask 255.255.251.0 (gateway IP)
So far, neither route table addition looks like our answer.
HOWEVER, if you concede that it is highly probable that
all the class C subnets (those finishing with /24) start
with either 10.24 OR 10.30, then 10.x.32.0 with a mask of
255.255.248.0 will cover all IPs in the range 10.x.32.0 to
10.x.39.255. Making "d" the correct choice....
It it says d is right, then I would suggest the above
paragraph is the solution.
Anyone else care to have a go?
...care to kudos?
...care to flame?
Marko Cosic
>-----Original Message-----
>In article <08eb01c34a1a$ff2229e0$a601280a@phx.gbl>,
moon@lighting.com
>says...
>
>> You're right, Tom. /24 is 255.255.255.0. Any
explanation
>> why the answer is 255.255.248.0?
>
>Either the question has been mis-typed here or mis-
remembered.
>255.255.248 won't help cover all eight of those
addresses, which jump
>from 10.24.*.* to 10.30.*.*. You'd need at least a /13
(255.248.0.0)
>mask to cover all those.
>
>The question is also bogus because 10.*.*.* is private
NAT space, and
>would not be allocated by an ISP -- but even overlooking
that, the
>suggestion that you could simply apply one large mask to
the whole
>network and call it a day is specious at best. If you
were to do so,
>then people on this network would be unable to reach
people using the
>same ISP from elsewhere, i.e. 10.27.5.0/24 would be
unreachable.
>
>BAD question, nice troll.
>
>> >> >-----Original Message-----
>> >> >I need some help with the following subnet problem:
>> >> >
>> >> >"You are the new administrator of a 2000 node
network.
>> >> >There is only one router on the entire network,
which
>> >> >provides all the computers with Internet access. The
>> >> >company's ISP has assigned the following 8 network
>> >> >addresses to them:
>> >> >
>> >> >10.24.32.0/24
>> >> >10.24.33.0/24
>> >> >10.24.34.0/24
>> >> >10.30.35.0/24
>> >> >10.30.36.0/24
>> >> >10.30.37.0/24
>> >> >10.30.38.0/24
>> >> >10.30.39.9/24
>> >> >
>> >> >What subnet mask could you use to minimize the
>> >> complexity
>> >> >of the routing tables while maintaining the existing
>> >> >Internet connectivity?
>> >> >
>> >> >a. 255.255.252.0
>> >> >b. 255.255.255.252
>> >> >c. 255.255.255.248
>> >> >d. 255.255.248.0 "
>> >> >
>> >> >The answer is 'd.' Quite frankly I do not understand
>> >> what
>> >> >the problem is getting at nor how 'd' gives the
>> desired
>
>.
>