Want to protect your cyber security and still get fast solutions? Ask a secure question today.Go Premium

x
  • Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 883
  • Last Modified:

manual route summarization and supernetting

Is the following an example of manual route summarization.  Or is it an example of supernetting?

ps: If ripv2 or EIGRP were to summarize this route, it would advertise it as 192.168.1.0/24 right

192.168.0.0/24

192.168.1.0/24
                           ROUTER-------192.168.0.0/22----------------->
192.168.2.0/24

192.168.3.0/24

thanks
 
0
dissolved
Asked:
dissolved
  • 3
  • 2
2 Solutions
 
pseudocyberCommented:
Take the Octet you want to summarize and convert to binary.  Then figure out where they're all the same, and that's your "bit boundry".

So, in your case it's:

0      00000000
1      00000001
2      00000010
3      00000011

So, you take 6 bits plus the other 16 and you get the /22.

I think supernetting and summarization are the same thing - summarizing networks by creating a supernet.
0
 
dissolvedAuthor Commented:
Thanks pseudocyber.

1. So I put the octet of interest in binary, and compare. I find where they are similar.

2. I count the number of bits that are similar (6 bits in our above example).

3. Where do I go from here? Where did the "16" come from?
0
 
lrmooreCommented:
Let me see if I can shed some light on your questions..

Supernetting = using fewer mask bits than the "standard" classful mask to expand a network. For example, take a standard class C address, 192.168.0.0 /24. Start running out of addresses and so instead of /24, you use /23 which just doubled your available hosts. That is supernetting. Problem is that not all TCP/IP stacks will recognize anything less than a standard classful mask. Many old printers, etc..

Route summarization is just that, a summary of routes available through you. In your example, you know/have/own 4 Class C subnets and you broadcast to your next hop neighbor a single entry with /22 mask instead of 4 individual /24 entries. Since this is nothing more complicated than a route decision, little intelligence involved. Here, classful boundaries have no meaning. Consider these route entries:
Any and all of them can be used as route summaries, only the Class C could be considered a supernet, if you must label it anything other than what it is - a route summay...

172.16.0.0 /22
192.168.0.0 /22
10.10.0.0 /22




0
Independent Software Vendors: We Want Your Opinion

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

 
dissolvedAuthor Commented:
thanks! Finally I get the true answer of what supernetting is.

lrmoore:
whats the easiest way to manually summarize?
I got halfway with pseudocyber's method and got stuck.

Convert to binary, find what matches etc...
0     00000000  
1     00000001
2     00000010
3     00000011

I understand where the 6 bits came from. But how did we get a /22 mask from this?
Thanks
0
 
pseudocyberCommented:
The /16 comes from the OTHER two octets in the network portion.  The 192.168.  Then you're chopping the third octet in half.  So, those other two octets are 8 bits each.  8+8=16+6=22.

Supernetting is the opposite of subnetting.  So, you can say to yourself, suppose I move the subnet bits some to the LEFT - then would the subnets I have fit inside the supernet I've created.

So, if you have 192.168.1.0 you could subnet it into two with 192.168.1.0/25 and 192.168.1.128/25 right, then, in effect, you could summarize those two with the first network IP - 192.168.1.0/24 (because the range of hosts encompases your two subnets).
0
 
dissolvedAuthor Commented:
thanks a lot guys!
0

Featured Post

Receive 1:1 tech help

Solve your biggest tech problems alongside global tech experts with 1:1 help.

  • 3
  • 2
Tackle projects and never again get stuck behind a technical roadblock.
Join Now