1

On multiple channels a "rule" is that only same sized networks can be combined. But this is only a valid constraint, if the subnet mask needs to remain the same as of the nets to be combined, correct? If I have more space available, then the nets surely don't need to be same sized. Or am I totally off here?

seen here (around 5.40): https://www.youtube.com/watch?v=MnqP_TVwkbs

and here: https://www.geeksforgeeks.org/supe

TMOTTM
  • 121
  • 3
  • What they are trying to explain is that IP addresses, thus network addresses, are binary numbers. That means for each bit you shift the mask, you either double or halve the hosts portion of the network address. if you look at at IP addressing in binary (the way it really works), then it becomes clear. See the answers to this question. – Ron Maupin Dec 23 '19 at 23:11
  • Its totally unclear how in the video he concludes that 200.1.0010'0000.0000'0000 is divisible by 2^12. What does that even mean? See Minute 21.40 ff. – TMOTTM Dec 23 '19 at 23:27
  • If you really want to learn IPv4 addressing and subnetting, then carefully study all sections, in order, of both parts of this two-part answer. – Ron Maupin Dec 23 '19 at 23:31
  • According to the part on supernetting in the linked answer, it should be correct to say that the networks 10.1.3.0/24, 10.1.4.0/24, 10.1.5.0/24 and 10.1.6.0/24 can be combined into 10.1.0.0/21. Would that be correct? – TMOTTM Dec 23 '19 at 23:50
  • Look at the range of host addresses in 10.1.0.0/21 (first part of the answer). Are all those network addresses included, and are you breaking things by including addresses not in those networks that are possibly used elsewhere? It is all very simply binary math. – Ron Maupin Dec 23 '19 at 23:54
  • @RonMaupin Your first remark (are all networks included): I would say yes. Second remark (claiming possibly already used address space): True, the network claims space that might be already reserved elsewhere. But if that was not a concern, would it then be ok? – TMOTTM Dec 24 '19 at 11:10

0 Answers0