The Long and Winding Road wrote: > > The question sucks and so do the answer choices. Eight > *addresses* per > > subnet or eight subnets? If the former, a mask of > 255.255.255.248 would > be > > required - not 255.255.248.0. If the latter, I'd go with you > (sorta). Or > > perhaps a. if subnet zero weren't allowed for some reason > (but then you'd > > have 15 subnets plus subnet zero - not eight!). > > > > Nothing you do with a subnet mask makes a class B a class C. > If it was > > class B before you subnetted it, it isn't going to fall into > the class C > > range of addresses all of the sudden is it? If by "class C" > they mean a > > subnet with 254 host addresses, your answer isn't right > either. Your > > subnets (/21) would have 8190 hosts. In that case, there > isn't a valid > > answer at all because a class B subnetted for 254 hosts will > have > somewhere > > in the neighborhood of 255 subnets. > > > CL: I disagree. 172.16.0.0/21 gives you eight subnets, each > with a mask of > /24 - subnets 172.16.0.0/24 through 172.16.7.0/24, for example. > Think ISP / > BGP :-) >
Chuck, Interesting. As you pointed out, 172.16.0.0 /21 has networks: 172.16.0.0 - 172.16.7.255 172.16.8.0 - 172.16.15.255 so on and so on� Each of which, of course, can be further subnetted to /24: 172.16.0.0 /24 through 172.16.7.0 /24 so on and so on�. So I guess you came up with the most correct answer by looking ahead to the next step. I still think the question sucks. If you subnet a class B with a /21 mask, you wind up with 2046 usable hosts until you subnet it further. Somehow I came up with 8190 host for a /21 mask the first time around. Don�t know why I though /21 left 13 host bits? What�s funny is that Todd Lammle is coming to our Cisco User�s group next week. The title of his presentation is something to the effect of �Learn to Subnet in Your Head in XX Minutes.� I elected not to reserve a seat on the basis that it would be a waste of my time. Hmmmm����� Thanks Chuck, Scott Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=58640&t=58569 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
