Hey Terry, great to have you posting here. I'm a big fan of a some of your articles I have come across. Are you writing anywhere regularly?
-Marc On Tue, Apr 12, 2011 at 8:03 PM, Terry Slattery <[email protected]> wrote: > Steve, > > That matches the 10.20.4.0 subnet and 10.30.4.0 subnet, but it won't match > any hosts on either subnet, because the last octet is 0 and the wild-card > bits are zero (must match). > > I was looking for a wildcard mask of 0.10.0.255 to match all hosts on either > subnet. > > If you went further, you could have also come up with 0.255.0.255, to match > 10.x.4.x. > > -tcs > > On 4/12/11 12:15 AM, Di Bias, Steve wrote: >> >> Terry is right, I may have jumped the gun with the inverse mask statement >> (although it's mentioned this way in many documents). For Terry's experiment >> let's assume we want to match the voice vlan for buildings 20 and 30 >> (10.20.4.0 and 10.30.4.0). By breaking this down into binary and using >> AND/OR logic we can easily come up with our answer >> >> 00001010.00010100.00000100.0000000 >> 00001010.00011110.00000100.0000000 >> ---------------------------------- >> 00001010.00010100.00000100.0000000 = 10.20.4.0 >> >> 00001010.00010100.00000100.0000000 >> 00001010.00011110.00000100.0000000 >> ---------------------------------- >> 00000000.00001010.00000000.0000000 = 0.10.0.0 >> >> So the "wildcard" mask to match both buildings would be 0.10.0.0 >> >> Cheers! >> >> Thank you. >> >> Steve Di Bias >> Network Engineer - Information Systems >> Valley Health System - Las Vegas >> Office - 702- 369-7594 >> Cell - 702-241-1801 >> [email protected] >> >> -----Original Message----- >> From: [email protected] >> [mailto:[email protected]] On Behalf Of Terry Slattery >> Sent: Monday, April 11, 2011 6:58 PM >> To: Jay Taylor >> Cc:<[email protected]> >> Subject: Re: [OSL | CCIE_RS] offset-list and wild card mask >> >> Good answer, Jay. For everyone who thinks that the wild-card mask is the >> opposite of the subnet mask... >> >> I have a set of subnets that I need to match. The first octet is 10. The >> second octet is a building number. The third octet identifies the subnet in >> each building, and is "4" for the voice subnet, which is what I want to >> match. >> >> Build a wild-card mask that matches >> 10.x.4.x >> >> Is it the inverse of the subnet mask? >> >> -tcs >> >> On 7/22/64 2:59 PM, Jay Taylor wrote: >>> >>> Offset list is used to increment the metric of certain routes. >>> >>> In a wildcard mask a binary 0 means the bit must match and a binary 1 >>> means it does not have to match. This is reverse logic compared to a >>> normal subnet mask. Also, unlike a subnet mask the 1's and 0's do not >>> need to be contiguous. >>> >>> >>> On Mon, Apr 11, 2011 at 11:04 AM, Uli<[email protected]> wrote: >>> >>>> Hi Expert, >>>> >>>> Does anyone can explain to me about offset-list as I kind of confused >>>> with it. also, in my opinion that wild card mask is reverse of subnet >>>> mask, but someone told me it isn't ? >>>> >>>> >>>> Regards >>>> _______________________________________________ >>>> For more information regarding industry leading CCIE Lab training, >>>> please visit www.ipexpert.com >>>> >>> >>> >>> >> > > -- > Terry Slattery CCIE# 1026 > > _______________________________________________ > For more information regarding industry leading CCIE Lab training, please > visit www.ipexpert.com > _______________________________________________ For more information regarding industry leading CCIE Lab training, please visit www.ipexpert.com
