At 07:35 AM 11/29/01 -0500, Tel Khan wrote: >Hi folks, > >I dont fully undertand VLSM i have read this in the Sybex book and i'm still >at a loss, I would be grateful for some guideness. > >Sorry for beeing thick! > >Regards >Tel VLSM means you can variable length subnet masks.
192.168.0.0/24 is normally a "classic class C block". Let us say you want to break it up into two subnets, normally you would do 192.168.0.0/25 192.168.0.128/25 What VLSM lets you do is have this scenario. Say I want 3 subnets! 192.168.0.0/25 192.168.0.128/26 192.168.0.192/26 Notice, now I have Variable Length Subnet Masks! Normally, since subnet info is not passed into certain routing protocols at all, they trust on the subnet mask assigned on the router's interface. Obviously, with just that method, you can ONLY break them into the same subnet masks across all subnets. In the VLSM case, I can break them up dynamically into smaller and smaller pieces. You can expand this example to make tiny /30 networks too. Ultimately, it is not that magical. It just means you can pass these routes into one router's interface without getting it confused because the routing protocols that support VLSM carry the subnet mask information within the routing packets. -Carroll Kong Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=27671&t=27665 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
