Good lad. That's five bits that are the same.
remember when we write masks as /21 or /24 what we are saing is "the first 21 (or 24) bits represent the network. You had done the "hard" bit going to binary and spotting the pattern. That's five bits the same here, added to the first two octets 8+8+5=21.
Yup. You know more than you think
The thing about subnetting and summarisation is that it is NOT difficult. Some people struggle, unfortunately some people that teach struggle. The people they teach then struggle and so on, and we have lots of people struggling.
P.
Being the topic is hot, here's a challenge for some of you that are still trying to work this crazy thing out....
Summarize networks:
10.0.0.0 /16through
10.100.0.0 /16-
Doan
You can only summarized in multiples of 2's (2,4,8,16....), so the first
64 networks (0...63) is 2**6, leaving 10 (16 -6) as your netmask. Same goes for the next 32 networks (64..95), 2**5 = 32; 16 -5 is 11. The next group of 4 networks (96,97,98,99) is 2**2, 16 -2 is 14; leaving 10.100.0.0 by itself which is /16. BTW, 10.100.0.0/14 would include 10.101.x.x to 10.103.x.x also.Doan
Doan
Perhaps an easier way to see the solution, which Doan nailed, is to look at bits:
second octet only is being described.....
00-xxxxxx 00-000000 0 00-111111 6310.0.0.0 /10 covers 10.0.0.0 thru 10.63.0.0
next subnet:
10.64.0.0010-xxxxxx
010-00000 64 010-11111 9510.64.0.0 /11 covers 10.64.0.0 thru 10.95.0.0
next subnet:
10.96.0.0011000-xx
011000-00 96 011000-11 9910.96.0.0 /14 covers 10.96.0.0 thru 10.99.0.0
last subnet:
10.100.0.0 /16 just send it as is
Very easy. Only the first 9 bits are the same so the summarization is
10.0.0.0/9The Dude
See Doan's solution....
I think in a thread like this, it helps when posts don't disappear. Google says that yours will vanish in 3 days. People do google and for old threads like this you know If you are so worried about privacy, post anonymously!
Will you please repost Doan' solution, it is not on my outlook express anymore ....
Thanks
The Dude
He over-summarized. 10.0.0.0/9 is 10.0.0.0 netmask 255.128.0.0 and it covered 128 subets 10.0.0.0/16 through 10.127.0.0/16. The question only asked to summerize to 100.
Doan
I am not sure what your point is. ALL usenet posts disappear from servers, not just mine.
As for the anonymous bit - it is not so much for privacy but for three other reasons.
But yours disappear from google's archive
If you didn't see that I was getting at your posts disappearing from google's archive, then the rest of your response may not be relevant.
I never suggested you not posting to a NG. Of course I'm in favour of everybody benefiting from answers. That is why I think it's important to keep the post in the archive.
I didn't ask any question - cerainly not one that required help.
Though if you're referring to my question as to why you set your posts to disapepar from google's archive, I imagine that you really should be able to answer it better than others.
I didn't complain about you not answering. And I didn't complain about you not answering adequately. I'm glad you answered and i'm sure the answer is good. And I never said you were obligated to answer.
you defend that you answer, you defend that you don't answer. It sounds like you weren't sure what I was getting at and wanted to cover all possibilities. You should've just considered what I meant!! I can't have been any less difficult to understand than one of the books or routers you used for your CCIE!!! ;-)
Cabling-Design.com Forums website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.