I'm wondering whether it's worth me trying to explain my thought process after 6 pints of cider. But the six pints say YES - have a go. I'm too lazy to do the binary.
You've got to get used to the size of blocks involved with each mask. By that, I mean a /30 immediately suggests blocks of four. A /29 blocks of eight etc. You had four blocks of four (/30), so if they can be summarised in one statement it will have to be a block of 16, which should immediately suggest a /28. But!!! The blocks of 16 will be at 0, 16, 32......128, 144, 160....... This doesn't fit your group, so you're going to need more than one statement. With your second example.... Your /29 suggests blocks of 8. You have two blocks of 8, so IF it's going to fit, it will be a block of 16, which is a /28. The blocks will be 0, 16, 32, 48, 64.......... and your two blocks fit fine in to the above (between 48 and 64), so the summary address is 216.52.146.48 /28 Sorry if this is nonsense to some, but this is my thought process. I am not capable of doing the binary in my head. This process becomes so simple once you grasp it, and can be done in seconds for almost any summary address. It doesn't take any special brain, because I'd be out of the running, it's just hard to explain and grasp initally. Please let me know if I should give up now and go to bed. Until then, the fridge (or cooler if you like) beckons. Cheers, Gaz ""Kage Roc"" wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > I promise I will not be a knowledge leech, I will contribute what I know as > well. Ofcourse I do have a question regarding IP Summaization: Up untill > today I thought I had summarization down cold until I tried a few self made > excercises. The formula I used to gather a summ address was 2n=x. Thats 2 > to the n power equals x. > x is the number of subnets that you want to summarize and n will be how much > you subtract from the lowest mask of those subnets. for example: > > > 216.52.146.136/30 > 216.52.146.140/30 > 216.52.146.144/30 > 216.52.146.148/30 > > using that formula the summ would be 216.52.146.136/28 which is not a valid > route. Hoever that formula works here: > 216.52.146.48/29 > 216.52.146.56/29 > > summ route: 216.52.146.48 /28 > > I guess my question is, what is the best/effective/convient way to derive > summary addresses? Thanks for any input. Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=42268&t=41998 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
