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Cisco Wildcark Masking

Eoghan25 · 2007-07-11 11:35:11

hi has anyone anygood resources on the net for explaining this the testout cbt i have been using has been good but its is bit lacking on this. I can do it no problem for full subnets but for ranges of address i am bit lost on how to do it cheers, eoghan

11-07-2007 11:35am

#1

Eoghan25

Registered Users, Registered Users 2 Posts: 121 ✭✭

Join Date: April 2005

Posts: 38

hi has anyone anygood resources on the net for explaining this the testout cbt i have been using has been good but its is bit lacking on this. I can do it no problem for full subnets but for ranges of address i am bit lost on how to do it

cheers,

eoghan

0

Comments

#2 11-07-2007 1:03pm

_CreeD_

Registered Users, Registered Users 2 Posts: 4,162 ✭✭✭

Join Date: August 1999

Posts: 4022

Something I need to revise myself but essentially it comes down to mapping it out in binary as opposed to using the magic number trick and inverting the way you would for subnets. Line up your ranges in binary one under the other, then from left-right zero the bits that match up until the first column that doesn't, this is your stop point and from here '1' everything else. Convert back to the wilcard mask and you now have one that represents the range. It's basically an inverse of a route summary.

0