Introduction
There are many millions of routes on the internet. If these routes all had to be stored individually the internet would have come to a stop many years ago.
Route summarization is also knows as supernetting and was proposed in RFC 1338 which you can read
online by clicking on the RFC or if you have printed this document by visiting www.faqs.org/rfcs/rfc1338.html.
If you want to read a very comprehensive guide to route summarization then please grab a hold of Jeff Doyles excelling Cisco book Routing TCP/IP Volume 1 which is in its second edition now.
| ZIP Codes
ZIP codes were used by the United States Postal Service to improve routing of letters to addresses within the USA. The first digit represents a group of US states and then the second and third digits represent a region inside that group. The idea is that letters and parcels can be quickly routed by machine or hand into the correct state and then forwarded to that state. When it reaches the state it can be routed to the correct region. From there it can be routed to the correct city and so on until it is sorted into the correct mail bag for the local postman or lady. |
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The system was devised to make routing of mail more accurate and efficient.
The sorting office in Atlanta doesn’t need to know which street in San Francisco
Leave A Reply (2 comments So Far)
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howtonetwork-member
328 days ago -
mbond12
24 days agoHi Paul – >> is there a way to reverse engineer a route summary.
>> For example – if the route summary is given in cidr notation, how do
>> you work it backward to obtain what ranges were originally sumarized?How would I tell which networks are contained in the summarized cidr route of 192.168.64.0/19
Many thanks
Mark
I am a bit confused about exercise one. I understand why the subnet mask is a /17 but why is the third octave a “0″ and not “128″?
Using the first example the common bit is the 8 column in binary so the third octave will be an 8.
But in exercise one the common bit column is 128 but the third octave is a 0