Horongo, One of my first posts to OSL, so please be gentle!
Your summary seems to be correct, but it includes many addresses outside of the scope that you listed. Wouldn't it also match 172.16.38.0, 172.16.39.0, etc? If a question asks you to summarize and include ONLY a range of addresses, then you may need to break the address range down into several smaller sections that contain similar bit patterns. >From a quick look, the following ranges would summarize the addresses in your list: 172.16.31.0/24 172.16.32.0/22 172.16.36.0/23 Thanks, Michael On Wed, Jan 5, 2011 at 7:19 AM, Horongo MCPherson Tuahuku < [email protected]> wrote: > > I thought I mastered binary that I could even solve them by looking at it. > How wrong! Personally I had no problems with binary maths and every time I > saw it on my CCNA or CCNP exam I knew that they are my soft points. It seems > the way the instructor does binary tricks me somehow and I happen not to > follow. > > For example, I don’t understand why he would break 7 contiguous subnets > into three or more options when summarising them? Let’s take 172.16.31.0 – > 172.16.37.0 subnets. My understanding is that you convert all to binary and > look at the pattern ( common bits) and then come up with summary address. > Since the 1st two octets are similar, we should concentrate on the third > octet. > > > 128 64 32 16 > 8 4 2 1 > 172.16.31.0 0 0 0 1 > 1 1 1 1 > 172.16.32.0 0 0 1 0 > 0 0 0 0 > 172.16.33.0 0 0 1 0 > 0 0 0 1 > 172.16.34.0 0 0 1 0 > 0 0 1 0 > 172.16.35.0 0 0 1 0 > 0 0 1 1 > 172.16.36.0 0 0 1 0 > 0 1 0 0 > 172.16.37.0 0 0 1 0 > 0 1 0 1 > > Summary 172.16.0.0 /18? > > Hope to hear from you all. > > Regards, > > Horongo > > _______________________________________________ > For more information regarding industry leading CCIE Lab training, please > visit www.ipexpert.com > _______________________________________________ For more information regarding industry leading CCIE Lab training, please visit www.ipexpert.com
